-NRLF 


STANDARD  TABLES 


ELECTRIC  WIREMEN. 

WITH 

INSTRUCTIONS  FOR  WIREMEN  AND  LINE- 
MEN,    UNDERWRITERS'    RULES, 
AND  USEFUL  FORMULA 
AND    DATA. 


CHARLES  M.  DAVIS. 


FOURTH  EDITION, 

THOROUGHLY    REVISED    AND    EDITED   BY 
W.  D.  WEAVER. 


NEW 

COPYRIGHT,  1893, 
THE  W.  J.  JOHNSTON 

167-176  TIMES  BUILDING. 


PREFACE  TO  THIRD  EDITION. 


THE  revision  of  this  popular  work  had 
just  been  commenced,  when  it  was  sadly 
interrupted  by  the  death  of  Mr.  Davis, 
and  has  been  completed  by  other  hands. 

Much  that  was  alien  to  the  purpose  of 
the  book  has  been  discarded,  and  new 
material  so  extensively  introduced  as  to 
render  this  a  practically  new  work. 

The  wiring  tables  have  all  been  recalcu- 
lated on  a  uniform  basis  and  arranged  in 
a  more  convenient  manner  for  practical 
use. 

The  object  has  been  to  produce  a  book 
for  wiremen  thoroughly  reliable  and  prac- 
tical in  its  data,  and  free  from  verbiage 
and  padding. 


PREFACE  TO  FOURTH   EDITION. 


THE  new  insurance  rules  of  the  Under- 
writers' International  Electric  Association, 
which  havebeen  generallyadopted  through- 
out the  United  States,  and  will,  it  is  thought, 
finally  supersede  all  others,  have  been  sub- 
stituted in  the  present  edition. 

An  important  section  has  been  expressly 
prepared  for  this  edition  on  the  calculation 
of  alternating  current  wiring,  which,  for 
the  first  time,  brings  this  subject  within 
the  reach  of  practical  men. 

3 


NOTE.— In  order  to  still  further  improve 
future  editions  of  this  work,  suggestions  from 
those  using  it  are  cordially  invited  and  will 
receive  careful  consideration. 

Address 

Publishing  Department, 
THE  VV.  J.  JOHNSTON  Co.,  Ld., 

Times  Building,  New  York. 


SIZES  OF  CONDUCTORS  FOR  IN 
CIRCUITS. 

The  most  accurate  method  of  determin- 
ing the  proper  sizes  of  incandescent  lamp 
conductors  is  to  refer  all  measurements 
back  to  the  dynamo,  converter,  or  street 
tap. 

To  illustrate,  suppose  we  have  an  installa- 
tion of  150  lights,  consisting  of  a  feeder  or 
dynamo  main  20  feet  long  (to  distributing 
point)  and  several  mains  A,  B,  andC,  their 
lamps  and  lamp  centres  being  respectively 
60,  50,  and  40  in  number,  and  38,  60,  and  90 
feet  from  the  end  of  the  feeder.  Let  us 
calculate  the  sizes  of  the  feeder  and  one 
main,  and  of  one  branch  having  12  lamps 
with  centre  20  feet  from  the  main,  the 
branch  starting  18  feet  from  the  distribut- 
ing point.  (See  cut.) 


\~ 

—--33- 

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* 

<a| 

ii 

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~"~38'47 

To 



~®l|l 

<j 

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3 

1  — 

—  Lcr 

-r,o- 

- 

-  7 

0 

1 

0 

c 

] 

A 

40  LAMPS 

2           1 

Elec.  11 

' 

Q 

I 

Q.LL 

50 

U. 

^ 

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CNOC 

To  find  the  size  of  the  branch  wire,  refei 
to  the  appropriate  table  with  20  +  18  -f  20 
feet,  or  58  feet  for  12  lamps. 

To  find  the  size  of  the  main,  imagine  the 
branches  on  one  side  to  be  revolved  (or  lay 
them  out  thus  on  a  diagram)  so  that  all 
are  on  the  same  side  of  the  main  ;  then  esti- 
mate or  calculate  the  lamp  centre  of  the 
resultant  group,  which  in  this  case  we  will 
suppose  to  be  23  feet  from  the  main  and 
38  feet  from  the  distributing  point  measured 
along  the  main,  and  refer  to  the  table  with 
20  +  38  4-  23  feet  for  12  -f  30  -f  18  lamps, 
or  8 1  feet  for  60  lamps. 

To  find  the  size  of  the  feeder,  suppose 
the  mains  to  be  revolved  about  the  dis- 
tributing point  so  that  they  all  overlap, 
and  with  all  the  branches  on  one  side  of 
the  overlapping  mains ;  then  estimate  or 
calculate  the  lamp  centre  of  the  resultant 
group  (comprising  all  the  lamps),  which  in 
this  case  we  will  suppose  to  be  20  feet  from 
the  overlapping  mains  measured  at  right 
angles,  and  48  feet  from  the  distributing 
point  measured  along  the  main,  and  refer 
to  the  table  with  20  +  48  -f  20  feet  or  88  feet 
for  150  lights,  or  for  the  largest  number  of 
lights  that  will  ever  be  used  at  one  time. 


In  simple  cases  the  quantities  may  be 
estimated,  either  directly  (especially  for 
branches)  or  from  rough  diagrams,  and 
for  more  complex  cases  or  where  a  per- 
fectly accurate  result  is  desired,  the  follow- 
ing rules  are  given  : — 

For  BRANCHES,  follow  the  method  given 
above. 

For  MAINS,  multiply  the  number  of 
lamps  on  each  branch  of  a  main  by  the 
distance  of  their  lamp  centre  from  the 
distributing  point,  always  measured  along 
the  lead  of  the  main  and  branch  ;  add  the 
products  thus  obtained  for  all  the  branches 
on  the  main  and  divide  by  the  whole  num- 
ber of  lamps  on  the  branches.  Add  the 
length  of  feeder  and  refer  to  the  table  with 
the  resultant  distance  and  lamps. 

EXAMPLE.— (See  cut,  main  A.) 

(18  +  20)  x  12  =    456 

(33  +  3°)X3°  =  l89° 
(60  +  15)  x  18  =  1350 

45l±j8?o±I35o  +20  =  8l    feet   for  6o 
12  +    30    +    18 
lamps. 


For  FEEDERS,  add  the  sum  of  the  prod- 
ucts obtained  as  above  for  all  the  mains, 
divide  by  the  entire  number  of  lamps  on 
the  feeder,  add  the  length  of  the  feeder, 
and  refer  to  the  table  with  this  distance 
and  all  the  lamps  on  the  feeder,  or  the 
largest  number  that  will  ever  be  used  at 
one  time. 

EXAMPLE. — (See  cut.) 

Main  A.  456  +  1890  4-  1350  =  3696 

Main  B.  60    x     50    —  3000 

Main  C.  90    x    40    =  3600 

3696  +  3000  +  36oo       2Q  =  88  feet  for  ,  50 

150 
lamps. 

Care  must  be  taken  not  to  confound  a 
lamp  centre  (so  called)  with  a  geometrical 
centre.  For  example,  suppose  a  series  of 
branches  of  equal  length  radiating  from 
the  end  of  a  main  like  the  spokes  of  a 
wheel,  and  having  lamps  at  equal  intervals. 
Here  the  geometrical  centre  is  the  radiat- 
ing point,  while  the  lamp  centre  is  on  a 
circle  passing  through  the  centres  of  the 
various  groups,  or  the  length  of  the  radius 
from  the  radiating  point.  In  the  case  of 
the  mam  A  given  above,  the  geometrical 


centre  is  15  feet  from  the  main,  while  the 
true  lamp  centre  is  23  feet.  It  is  to  pre- 
clude the  error  of  geometrical  centres  that 
the  branches  and  mains  are  laid  clown,  or 
imagined,  revolved. 

SUB-BRANCHES  and  TAPS  may  in  general 
be  considered  as  groups  of  lamps  directly 
on  the  branch  itself  and  thus  included  in 
the  calculation  for  the  branch. 

The  above  method  is  applicable  to  all 
systems  of  wiring,  and  is  particularly  val- 
uable and  economical  in  securing  proper 
distribution  of  light  on  low  voltage  circuits 
having  a  small  percentage  of  loss.  By 
stringing  the  branches  first,  when  possible, 
this  method  may  be  easily  followed  without 
the  aid  of  a  diagram,  even  in  complex  cases. 
With  the  "  closet  "  system  of  wiring,  dia- 
grams and  calculations  as  a  rule  will  not  be 
required. 

The  "  tree  "  system  of  wiring  is  to  be 
avoided  where  possible,  on  account  of 
the  unequal  distribution  of  light  it  entails. 
In  many  cases  secondary  centres  of  dis- 
tribution may  be  substituted,  and  if  care- 
fully calculated  the  weight  of  wire  in  the 
latter  case  need  not  exceed  that  in  the 
former. 


The  voltmeter  should  always  be  con- 
nected with  the  centre  of  distribution  and 
not  with  the  feeder  near  the  dynamo,  un- 
less it  is  desirable  to  have  a  steady  light  in 
a  particular  locality,  when  it  should  be  con- 
nected with  the  line  there. 

Owing  to  the  exceedingly  small  current 
passing  through  a  voltmeter,  the  resistance 
of  even  a  very  small  wire  in  ordinary  cases 
will  not  practically  affect  its  readings. 
Where  the  line  is  very  long,  a  No.  12  or  14 
insulated  iron  wire  may  be  used  and  the 
voltmeter  at  the  dynamo  set  once  for  all 
by  comparison  with  a  standard  voltmeter 
temporarily  attached  at  the  point  which 
is  to  be  maintained  at  a  constant  potential, 


10 


WIKING  FORMULJE  AND  TABLES. 

Tables  I-IV  were  calculated  on  the 
basis  of  55  watt  16  candle-power  lamps. 
While  there  are  lamps  taking  somewhat 
less  current  than  the  above,  it  is  advisable 
to  allow  some  margin  in  wiring. 

The  formula  deduced  for  calculating  the 
tables  is 

A  =  *!*£-  LN.    ...(,) 
ah1 

where  A  =  section  in  circular  mils. 
W  =  watt  rating  of  lamps. 
E  =  voltage. 
L  =  distance  to  centre  of  distribu- 

tion, in  feet. 
AT  =  number  of  lamps. 

a=  percentage  of  drop. 
The  AMPERES  (C)  being  given,  the  size 
of  wire  in  circular  mils  can  be  found  from 
the  following  formula: 


EXAMPLE.  Volts,    50;     amperes,    100; 
feet  to  centre  of  distribution,  100;  drop,  2^. 

2150  x  TOO  x  100  .       , 

—  =  215,600  circular  mils. 
2  x  50 

By  referring  to  table   IX,  page   30,  we 
find  this  to  be  about  No.  oooo  B.  &  S. 
IT 


The  HORSE-POWER  (H.  P.)  and  efficiency 
(eff-}  of  a  motor  being  given,  the  size  of 
the  conducting  wire  in  circular  mils  can 
be  found  from  the  following  formula  : 

160,400,000  x  H.  P.  x  L 


EXAMPLE.  Horse-power,  10;  volts,5oo; 
drop,  3$;  feet  to  distributing  point,  600; 
efficiency  of  motor,  75$. 

160,400,000  x  10  x  600 
A=—         -  =17,109. 
3  x  500  x  500  x  75 

Referring  to  table  IX,  page  30,  we  find 
this  to  be  about  No.  8  B.  &  S. 

The  gauge  may  be  directly  taken  from 
the  tables  below  500  volts  by  means  of 
the  following  formula  of  lamp  equivalent, 
(0: 


.  .  .  « 

EXAMPLE.  Horse-power,  5;  volts,  no; 
drop,  3^;  feet  to  distributing  point,  200-; 
efficiency  of  motor,  75^. 

1360  x  5 
Q  =  -  =  lamp  equivalent  =  90. 


12 


Referring  to  table  III,  we  find  that  No.  2 
B.  &  S.  wire  corresponds  to  90  lamps  and 
200  feet,  the  drop  being  3$. 

If  the  distance  had  been  400  feet,  we 
could  still  have  referred  to  the  2oo-feet 
column,  but  with  2  x  90  or  1  80  lamps. 

Having  the  HORSE-POWER,  and  effi- 
ciency of  a  motor  to  go  on  a  5oo-volt  cir- 
cuit, to  find  the  amperes  with  which  to 
enter  Table  V,  or  to  apply  formula  (2),  we 
have  the  following: 


EXAMPLE.  Horse-power,  7^;  efficiency, 

W 

r      7i  x  H9 

C  =  -  —  -  =13-9  amperes. 

Table  IV.  is  also  a  220-VOLT  table,  and 
can  be  used  as  such  for  motor  wiring  by 
means  of  formula  (4). 


WIRING 

50 

NUMBER  OF  LAMPS. 

Per  cent  of  Loss. 

16  (j.  f.  LAMPS. 

I* 

*% 

3* 

W  1% 

10* 

20' 

25' 

30'  35'  40' 

45' 

50' 

i 

1 

1 

2 

g 

5 

1G 

16 

16  16 

16 

16 

16 

1 

2 

3 

4 

5 

10 

16 

16 

16  16 

16 

16 

16 

1 

3 

4 

6 

1 

15 

1G 

1G 

,  16 

16 

15 

15 

14 

2 

4 

6 

8 

j  10 

20 

1G 

10 

15  15 

14 

14 

13 

2 
3 

5 
6 

7 
9 

10 
12 

\i 

25 
30 

16 
15 

15 
14 

14 
14 

14 
13 

13 
12 

13 
12 

12 
11 

3 

4 

7 

8 

10 
12 

14   17 

16   20 

35 

40 

14 
14 

14 
13 

13 
12 

12 

12 
11 

11 
11 

11 

10 

4 

9 

13 

18 

22 

45 

13 

12 

12 

11 

11 

10 

10 

5 

10 

15 

20 

25 

50 

12 

12 

'  11  11 

10 

10 

9 

6 
7 

12 
14 

18 
21 

24 

28 

30 
35 

60 
70 

11 

11 
11 

11  10 
10  9 

9 
9 

9 

8 

9 

8 

8 

16 

24 

32 

40 

80 

11 

10 

9!  9 

8 

8 

„ 

9 

18  27 

36 

45 

90 

10  10 

9   8 

g 

rt 

10 

20  30 

40 

50 

100 

10 

9 

8  8 

7 

6 

12 

25j  37 

50 

62 

125 

g 

8 

8 

^ 

6 

5 

15 

30  45 

60 

150 

8 

8 

r- 

G 

5 

5 

4 

17 

35 

52 

70 

87 

175 

8 

7 

6 

5 

5 

4 

4 

20 

40 

60 

80 

100 

7' 

6 

G 

5 

4 

4 

3 

22 
25 

45 

50 

67 
75 

90 
100 

112 

125 

6 

G 
5 

5 
5 

4 
4 

4 
3 

3 

3 

0 

27 

55 

82 

110 

137 

G 

5l  4 

3 

3 

2 

30 

60 

90  120 

150 

5 

5 

4 

2   9 

32 

65 

97  130 

162 

5 

4 

3  3 

2 

2 

1 

35 

70 

105 

140 

5 

4 

3  2 

o 

1 

j 

40 

80 

120 

160 

4 

a 

3  2 

1 

o 

45 

90 

135 

3 

8 

2  1 

1 

0 

0 

50 

100 

150 

3 

o 

2i  1 

Q 

o 

00 

55 
60 

110 
120 

165 

3 

2 

2 

1 
1 

0 
0 

00 

00 
00 

00 
000 

65 

130 

2 

1 

o'  o 

00  00 

000 

70 
75 

140 
150| 

2 
1 

1 
0 

0  00 
0  00 

00  1  000 
OOj  000 

000 
0000 

B.  &  S. 

GAUGE. 

HKAT- 

ING 

LIMITS. 

S£ 

P 

SiS 

A 

60' 

70' 

80' 

90'  jlOO' 

120'  140'  160' 

180' 

200' 

16      16 

16 

16     16 

15      15      14 

14 

13 

16|      4 

15 

15 

14 

14 

13 

12      12      11 

11 

10 

14       9 

14 

13 

18 

12 

11 

10     10       9 

9 

8 

I-,'      13 

10      18 

12 

12 

11 

11 

10 

9 

9       8 

8 

y 

8'     22 

11 

11 

10 

10 

9 

9 

8       7 

7 

6 

7     27 

11 

10 

9 

9 

8 

8 

6 

6 

5 

6 

31 

5 

41 

10 

9 

9 

8 

8 

7 

6 

6 

5 

5 

4 

45 

9 

9 

8 

8 

7 

6 

6 

5 

4 

4 

a 

54 

'.< 

8 

8 

7 

6 

6 

5 

5 

4 

4 

•_>      63 

1      86 

9 

8 

7 

7 

6 

5 

5 

4 

4 

3 

0     90 

8       7 

6 

6 

5 

5 

4 

3 

3 

2 

00'  100 

7;     o 

6 

5 

5 

4 

3 

3 

2 

2 

000    1*1 

0000    160 

6 

6 

5 

5 

4 

3 

3       2 

2 

1 

6 

5 

5 

4 

3 

3 

2       2 

1 

1 

5 

5 

4 

4 

3 

2 

2       1 

1 

0 

5 

4 

3 

3 

2 

2 

1 

0 

0 

0 

4 

3 

3 

2 

1 

1 

0       0 

00 

00 

3 

2 

2 

1 

1 

0 

0      00 

000 

000 

0 

2 

1 

1 

0       0 

00 

000 

000 

0000 

1 

I 

1 

0 

0 
0 

0|     00 

00    000 

000 
000 

0000000 

ooooloooo 

0000 

1!       0 

0     00 

CO   0000000 

0000 

1        0 

00     00 

000    0000000 

0       0 

00     00 

0000000,0000 

0 

00 

00 

000 

0000000 

0 

00 

000   000 

00000000 

00 

000 

0000000 

0000 

00 

00000000000 

000 

0000 

0000 

000 

0000 

3000  0000 

WOO, 

KX)0 

WIRING 

75 

NUMBER  OF  LAMPS. 

16  C.  P.  LAMPS. 

Per  cent  of  Loss. 

\% 

2£ 

3# 

4£ 

5fe 

10* 

20'  25' 

30' 

35'  40' 

45' 

50' 

~ 

11   1 

2 

2   5 

16!  16  16 

16  16 

16 

16 

1 

2 

2 

4 

5i  10 

10  10  10 

16  16 

16 

16 

1 

3 

4 

6 

15 

16  16:  16 

16  16 

16 

16 

2 

4 

6 

8 

10 

20 

10  10  16 

1$  16 

16 

16 

2 

5 

10 

12 

25 

16  16  16 

16  16 

16 

16 

3 

6 

9 

12 

15 

30 

10  10  10 

10  16 

15 

15 

3 

7 

10 

14 

17 

35 

10'  16  10  10  15  15   14 

4 

8 

12 

10 

20 

40 

16 

16  16 

15  15  14  !  14 

4 

9 

13 

18 

22 

45 

10 

16 

15 

15  14 

14 

13 

5 

10 

15 

20 

25 

50 

10 

16 

15 

14  14 

13 

13 

6 

12 

18 

24 

30 

60 

10 

15|  14 

14  13 

12 

12 

7 

14 

21 

28 

35 

70 

15 

14 

14 

13 

12 

12 

11 

8 

16 

24 

32 

40 

80 

14 

14 

1-3 

12 

12 

11 

11 

9 

18 

27 

30 

45 

90 

14 

19 

12 

12 

11 

11 

10 

10 

20 

30 

40 

50 

100 

14 

13 

12 

11 

11 

10 

10 

12 

25 

37 

50 

62 

125 

18 

12 

11 

10 

10 

9 

9 

15 

30 

45 

60 

75 

150 

12 

11 

10 

10 

9 

9   8  j 

17 

35 

52 

70 

87 

175 

11 

10 

10 

9 

9 

8j  rl 

20 

40 

60 

80 

100 

200 

11 

10   <) 

8 

8 

7   7  i 

22 

45 

67 

90 

112 

225 

10 

9   9 

8 

7i  7   0 

25 

27 

50  75 

55!  82 

100 
110 

125 
137 

250 

10 
B 

Q 

9 

8 
8 

6 

0 
6 

0 
5 

30 

60|  90 

120 

150 

8 

8  7 

7 

6  5 

5 

32 

65 

97 

130 

162 

g 

8  7 

0 

0   5 

5 

35 

70 

105 

140 

175 

8 

7'  7 

6 

5   5 

4 

40 

80 

120 

160 

200 

8 

7  6 

5 

5  4 

4 

45 

90 

135 

180 

225 

7 

6 

5 

5 

4!  4 

3 

50 

100 

150 

200 

250 

M 

6 

5 

4 

4  3 

3 

55 

110 

165 

220 

6 

5 

5 

4 

3  3 

2 

60 

120 

180 

240 

0 

5 

4 

4 

3  a 

2 

65 

130 

195 

5 

5 

4 

3 

3  2 

j> 

70 

140 

210 

5 

4 

4 

3 

2   2 

1 

75 

150 

225 

5 

4  3 

3 

2,  1 

1  j 

16 


TABLE   II. 
VOLTS, 


B.  &  S.  GAUGE. 

HEAT- 

ING 

LIMITS. 

II 

-| 

60' 

70' 

80' 

90' 

100'  1  120' 

140' 

160'  180'  200' 

5^ 

fc'J 

16 

16 

16 

16 

16  16 

16 

16   16  16 

16 

6 

16 

16 

16 

16 

16  16 

15 

15   14   14 

14 

13 

16 

16 

16 

15 

15 

14 

14 

13   12   12 

12 

20 

10 

27 

16 

15 

14 

14 

14 

13 

19 

12   11 

11 

8 

34 

15 

14 

13 

13 

13 

12 

11 

11   10 

10 

7 

40 

14 

14 

13 

12 

12 

11 

10 

10   9 

9 

6 

44 

5 

61 

14 

13 

12 

12 

11 

10 

10 

9'   9 

8 

4 

68 

13 

12 

12 

11 

11 

10 

9 

9   8 

8 

3 

81 

13  I  12 

11 

11 

10 

9 

s 

8   8 

7 

2 

95 

1 

129 

12  11 

11 

10 

10 

9 

S 

7 

7 

0 

136 

11 

10 

10 

9 

9 

8 

8 

7   6 

6 

00 

16? 

11 

10 

9 

9 

8 

7 

6   6 

5 

000 

197 

0000 

240 

10 

9 

9 

S 

8r>'    /• 
7   6 

6 

5 

5 

i) 

9 

8 

8 

7   7 

6 

5 

4 

4 

9 

8 

8 

7 

0 

5 

5 

4 

4 

8 

7 

6 

6   5 

5 

4 

3 

a 

7 

7 

6 

6 

5   4 

4 

3 

3 

5j 

7 

6 

5 

5 

4 

4 

3 

2 

* 

1 

6 

5 

5 

4 

4 

3 

2 

2 

1 

1 

5 

5 

4 

4 

3 

2 

2 

1 

1 

0 

5 

4 

4 

3 

3 

2 

1 

I 

0 

0 

5   4 

3 

3 

2 

o 

1 

0 

0 

00 

4   4 

3 

o 

2 

1 

1 

0 

00!  00 

'43 

3 

2 

2 

1 

0 

0 

00  00 

4   3 

2 

0 

1 

0 

0 

00 

00  000 

1 

3   2 

2 

] 

1 

0 

00  00 

000  000 

i 

2 

2 

1 

1 

0 

0 

oo  ooo 

0000000 

I 

2 

1 

1 

0 

0 

00 

ooo1  ooooooo-oooo 

2 

1 

1 
1 

0 
0 

0 

00 

00 
00 

00 

000 

ooooooojoooo 
oooooool 

1 

0 

0 

00 

00 

000  0000  0000  i 

1 

0 

00 

00 

000 

0000000 

0   0 

00 

000 

000  0000  0000 

NUMBER  OF  LAMPS. 

16  C. 

P.  LAMPS. 

Per  cent  of  Loss. 

1% 

& 

8* 

4% 

5*  1  10* 

'-. 

25' 

30'  35' 

40'  45' 

50' 

| 

1 

1 

o 

21   5 

16 

16 

16 

16  16 

16 

1 

2 

3 

4 

5   10 

16 

16 

16 

16 

16  16 

16 

1 

3 

4 

6 

7 

15 

16 

16 

16 

16 

16,  16 

16 

2 

4 

6 

8 

10 

20 

16 

16 

16 

16 

16 

16 

16 

5 

71  10 

25 

16 

16 

16 

16 

16 

16 

16 

3 

6 

9 

12 

15 

30 

16 

16 

16 

16 

16 

16 

16 

3 

7 

10 

14 

17 

35 

16 

16 

16 

16 

16 

16 

16 

4 

8 

12 

16 

20 

40 

16 

16 

16 

16 

16 

16 

16 

4 

9 

13 

18 

45 

16 

16 

16 

16 

16 

16 

16 

5 

10 

15  20 

25 

50 

16 

16 

16 

16 

16 

16 

16 

6 

12 

18 

24 

30 

60 

16 

16 

16 

16 

16 

15 

15 

7 

14 

21 

28 

35 

70 

16 

16 

16 

16 

15 

15 

14 

8 

16 

24 

32 

40 

80 

16 

16 

16 

15 

15 

14 

14 

0 

18 

27 

36 

45!  90 

16 

16 

15 

15 

14i  14 

13 

10 

20 

30 

40 

50 

100 

16 

16 

15 

14 

14 

13 

13 

12 

25 

37 

50 

62 

125 

16 

15 

14 

18 

13 

12 

12 

15 

30 

45 

60 

75 

150 

15 

14 

13 

18 

12 

11 

11 

17 

35 

52 

70 

87 

175 

14 

14 

13 

12 

11 

11 

11 

20 

40 

60 

80 

100 

200 

14 

13 

12 

12 

11 

10 

10 

22 

45 

67 

90 

112 

2:25 

13 

12 

12 

11 

10 

10 

9 

25 

50 

75 

100 

125 

250 

18 

12 

111  11 

10 

9 

9 

27 

55 

82 

110 

137,  275 

12 

12 

11 

10 

9 

9 

9 

30 

60 

90 

120 

150 

300 

12 

11 

10 

10 

9 

9 

8 

32 

65  97 

130 

162 

325 

12 

11 

10 

9 

9 

8 

8 

35 

70  105 

140 

175 

350 

11 

11 

10 

9 

9 

8 

8 

40 

80  120 

160 

200 

11 

10  9 

9 

8 

7 

7 

45 

90  135 

180 

225 

10 

10  9 

8 

7 

7 

6 

50 

100  150 

200 

250 

10 

9 

8 

8 

7 

6 

6 

55 

1101  155 

220 

275 

9 

9 

8 

7 

6 

6 

5 

60 

120 

180 

240 

300 

9 

8 

7 

7 

6 

6 

5 

65 

130 

195 

260 

325 

9 

8 

7 

6 

6 

5 

5 

70 

140 

210 

280 

350 

9 

8 

7 

6 

5 

5 

4 

75 

150  225 

300 

8 

7  6 

6 

5 

5 

4 

18 


TABLE    III. 
VOLTS. 


^ 

B.  &  S.  GAUGE. 
\ 

HEAT- 
ING 
LIMITS. 

1 
5* 

c  ~ 
z- 

60'   ro' 

80' 

90' 

100' 

120' 

140' 

160' 

180' 

200' 

10      16 

1G 

16 

16 

16 

16 

16 

16 

10 

16 

10 

16 

16 

16      16 

16 

16 

16 

16 

16 

16 

14 

20 

16 

16 

16 

16 

16 

16 

16 

16 

15 

15 

12 

30 

10 

40 

16 

16 

16 

16 

16 

16 

15 

15 

14 

14 

S 

50 

16 

16 

16 

16 

16 

15 

14 

14 

13 

13 

? 

60 

16 

16 

16 

15 

15 

14 

14 

13 

12 

12 

6 

70 

5 

90 

16 

16 

15 

15 

14 

14 

13 

12 

12 

11 

4 

100 

16 

15 

15 

14 

14 

13 

12 

12 

11 

11 

3 

120 

15 

15 

14 

14 

13 

12 

12 

11 

11         10 

2 

140 

1 

190 

15 

14 

14 

13 

13 

12 

11 

11 

10       10 

0 

200 

14 

14 

13 

12 

12 

11 

11 

10 

9         9 

00 

-,'40 

14 

13 

12 

12 

11 

11 

10 

9 

U          9 

000 

290 

0000 

350 

13 

1-2 

12 

11 

11 

10 

9 

9 

8 

8 

12 

12 

11 

11 

10 

9 

1) 

8 

8 

rt 

12 

11 

11 

10 

10 

9 

9 

8 

7 

1 

11 

10 

10 

9 

9 

8 

8 

7 

6 

6 

10 

10 

9 

9 

8 

7  • 

7 

6 

6 

5 

10       9 

9 

s 

8 

7 

6 

5 

5 

4 

9       9 

8 

7 

7 

6 

5 

5 

4 

4 

9       8 

7 

7 

6 

6 

5 

4 

4 

3 

8 

8 

7 

6 

6 

5 

4 

4 

3 

3 

8 

7 

6 

6 

5 

5 

4 

4 

3         3 

7       7 

6 

6 

5 

4 

4 

33         2 

7 

6 

6 

5 

5 

4 

3 

3 

~ 

2 

7 

6 

5 

5 

4 

4 

3 

2 

2 

1 

6 

5 

5 

4 

4 

3 

2 

2 

1 

1 

6 

5 

4 

4 

a 

3 

2 

1 

1 

0 

5 

4 

4 

3 

3 

o 

1 

1 

0 

0 

5 

4 

3 

3 

9 

2 

1 

0 

0 

00 

4 

4 

3 

3 

2 

1 

1 

0 

0 

00 

4 

3 

3 

2 

2 

1 

0 

0 

00 

00 

4 

3 

2 

2 

1 

1 

0 

00 

00 

000 

3 

3 

2 

1 

1 

0 

0 

00     00 

000 

THREE-WIRE    SYSTEM. 


NUMBER  OF  LAMPS. 

16  C.  P.  LAMPS. 

Per  cent  of  Loss. 

1% 

2* 

3# 

\% 

5# 

20' 

25' 

30' 

35'  |  40' 

45'  !  50' 

2 

5 

7 

10;  12 

16 

16 

~16~ 

16 

16 

16   16 

5 

10 

15 

20 

25 

16 

16 

16 

16 

16 

16 

16 

7 

15 

22 

30 

37 

16 

16 

16 

16 

16 

16 

16 

10 

20 

30 

40 

50 

16 

16 

16 

16 

16 

16 

16 

12 

25 

37 

50 

62 

16 

16 

16 

16 

16 

16 

16 

15 

30 

45 

60 

75 

16 

16 

16 

16 

16 

16 

16 

17 

35 

52 

70 

87 

16 

IP 

16 

16 

16 

U> 

16 

20 

40 

60 

80;  100 

16 

16 

16 

16 

16 

16 

16 

22 

45 

67 

90  1  112 

16 

16 

16 

16 

16 

16 

15 

85 

50 

75 

100 

125 

16 

16 

16 

16 

16 

15 

15 

27 

55 

82 

110 

137 

16 

16 

16 

16 

16 

15 

15 

30 

60 

90 

U'O 

150 

16 

16 

16 

16 

15 

15 

14 

32 

65 

97 

130 

162 

16 

16 

16 

15 

15 

15 

14 

35 

70 

105 

140 

175 

16 

16 

16 

15 

15 

14 

14 

40 

80 

120 

160 

200 

16 

16 

15 

14 

14 

13 

13 

45 

90 

135 

180 

225 

16 

16 

15 

14 

14 

13 

13 

50 

100 

150 

200 

250 

16 

15 

14 

13 

13 

12 

12 

55 

110 

165 

220 

275 

15 

15 

14 

13 

13 

li 

12 

60 

120 

180 

240 

300 

15 

14 

13 

13 

12 

11 

11 

65 

130 

195 

260 

325 

15 

14 

13 

13 

12 

11 

11 

70 

140 

210 

280 

350 

14 

14 

13 

12 

11 

11 

11 

80 

160 

240 

320  !  400 

14 

13 

12 

12 

11 

10 

10 

90 

180 

270  360!  450 

13 

12 

12 

11 

10 

10 

9 

100 

200 

300!  400  500 

13 

12 

11 

11 

10 

9 

9 

112 

225 

337 

450  562 

13 

12 

11 

10 

10 

9 

9 

125 

250 

375 

500  625 

12 

11 

11 

10 

9 

9 

8 

137 

275 

412 

550  687 

12 

11 

10 

10 

B 

9 

8 

150 

300 

450 

600  750 

11 

10 

9 

9 

9 

8 

8 

175 

350 

525 

700 

11 

10 

9 

9 

8 

7 

7 

200 

400 

600 

10 

9 

8 

8 

6 

6 

225 

450 

675 

10 

9 

8 

7 

6 

6 

250 

500 

750 

9 

8 

7 

7 

6 

6 

5 

300  |  GOO 

8 

1 

6 

6 

5 

4 

TABLE   IV. 

LAMPS. 


THREE-WIRE   SYSTEM. 


B.  &  S.  GAUGE. 

HE 
ii 

LllM 

II 

C^ 

-AT- 
s'G 
[ITS. 

°t 

6  a 
fc  J 

60' 

TO'  '  80' 

90' 

100' 

120'  140' 

160' 

180'  200' 

16 

16  16 

16 

16 

16   16 

16 

16   16 

16 

20 

16 

16  16 

16 

16 

16   16 

16 

16  15 

14 

40 

16 

16  16 

16 

16 

16  15 

15 

15 

14 

12 

60 

10 

80 

16 

16   16 

16 

16 

15   14 

14 

13 

13 

8 

100 

16 

16   16 

15  15 

14  14 

13 

13 

12 

7 

120 

16 

16  15 

15 

14 

H   13 

13 

12 

11 

6 

140 

5 

180 

16 

15  ;  15 

14 

14 

13  13 

12 

12 

11 

4 

200 

15 

14  !  14 

13 

13 

12  ,  11 

11 

10 

10 

3 

240 

15 

14  !  14 

13 

13 

12   12 

11 

11 

10 

2 

280 

1 

380 

14 

14 

13 

13 

12 

12   11 

11 

10 

9 

0 

400 

14 

14 

13 

13 

12 

11   11 

10 

10 

9 

00 

480 

14 

13 

13 

12 

12 

11   10 

10 

9 

9 

000 

580 

0000 

roo 

13 

13 

12 

12 

11 

10  10 

9 

9 

8 

13 

13 

12 

11 

11 

10   10 

9 

9 

8 

12 

11 

11 

10 

10 

9   9 

8 

8 

7 

12 

11 

11 

10 

10 

9 

9 

8 

8 

7 

11 

10 

10 

9 

9 

8 

8 

7 

7 

6 

11 

11 

10 

9 

9 

8 

8 

7 

7 

6 

10 

10 

9 

9 

8 

7 

7 

6 

6 

5 

10   10 

9 

9 

8 

7 

7 

6 

"  6 

5 

10   9 

9 

8 

8 

7 

6 

5 

5 

4 

9   9 

8 

7 

7 

6 

5 

5 

4 

4 

9   8 

7 

7 

6 

6 

5 

4 

4 

3 

8   8 

7 

6 

6 

5 

4 

4 

3 

3 

8 

8 

7 

6 

6 

5 

4 

4 

3 

3 

8 

7 

6 

6 

5 

5 

4 

3 

3 

2 

7 

7 

6 

5 

5 

4 

3 

3 

3 

2 

f 

6 

6 

5 

5 

4 

3 

2 

2 

1 

6 

5 

5 

4 

4 

3 

2 

2 

1 

1 

5 

A 

4 

3 

3 

2   1 

1 

0 

00 

5 

4 

4 

3 

3 

2   1 

1 

0 

00 

4 

4 

3 

2 

2 

1   1 

0   0  000 

3 

3   2 

1 

1 

0   0 

00  00  000 

B.  &  S.  GAUGE, 
Percent  Loss. 


Amperes  <it  top  of 


2$ 

b% 

10£ 

o 

4 

6 

8 

10 

14 

0000 
000 
00 

122500 
97000 
77000 

61125 
48500 
38400 

40750 
32*90 
25660 

30560 
24250 
19250 

24450 
19400 
15400 

17460 
13835 
11000 

0000 
000 
00 

0 

1 
o 

61110 
48600 
38600 

30550 
24300 
19300 

20375 
16200 
12875 

15275 
12150 
9650 

122-30 
9720 
7720 

8730 
6945 
5520 

0000 
000 

0 

1 

o 

3 
4 
5 

30600 
24250 
19250 

15300 
12125 
9625 

10210 
8075 
6410 

7650 
6065 
4810 

6120 
4850 
3850 

4375 
3465 
2750 

00 
0 

1 

3 
4 
5 

6 

7 
8 

15200 
12100 
9610 

7600 
6050 
4805 

5080 
4040 
3200 

3800 
3025 
2400 

3040 
2420 
1U20 

2180 
1730 
1375 

o 
3 
4 

6 

7 
8 

9 
10 
11 

7600 
6050 
4800 

3800 
3025 
2400 

2535 
2015 
1600 

1900 
1510 
1200 

1520 
1210 
960 

1090 
865 
6H5 

5 
6 

9 

10 
11 

12 
13 
14 

3800 
3010 
2400 

1900 
1505 
1200 

1265 
1000 
800 

950 
750 
600 

760 
600 
480 

545 
430 
340 

8 
9 
10 

12 
13 
14 

15 
16 

1900 
1510 
1200 

950 
760 
600 

635 
500 
400 

475 
375 
300 

380 
300 
240 

270 
215 
170 

11 
12 
13 

15 
16 

950 
755 
600 

478 
380 
300 

315 
250 
200 

235 

185 

190 

14 

475 

240 

- 

15 
16 

37'5 
300 

190 

ABLE   V. 

OLTS. 

V\^  v     • 

\    /""")           r~ 

'tliunnx.  Feet  below. 

\&    &  •< 

1                                                   \  ^     4 

20 

30           40 

50 

75    '     100 

150  |"  200 

8220 

8150       6110 

4890 

3260      2445 

1630      1222 

9700       6455        4850 

3875 

2580      1940 

1290 

970 

7700  I    5130 

3850 

3080 

2050     1540 

1025 

770 

j 

6110 

4075 

3055 

2445 

1630      1220 

815 

610 

4860 

3240 

2430 

1945 

1295  I     970 

650 

485 

3860       2575 

1930 

1545 

1030 

770 

515 

385 

1060  !    2040 

1530 

1225 

815 

610 

410 

305 

2425 

1615 

1215 

970 

645 

485 

325 

240 

1935 

1280 

960 

770 

515 

385 

260 

195 

1520 

1<15 

760 

610 

405       304 

200 

BIO  |      810         605 

485 

325 

240 



960         (340         480 

385 

255 

190 

760 

510 

380 

305 

200 

605 

400 

300 

240 

480 

320 

240 

190 

380 

250 

190 

HEATING 
LIMITS  FOR 

300 

200 

INTERIOR 

240 

\VIRINO. 

190 

iauge 

Amp. 

• 

16 

5 

14 

10 

12 

15 

10 

20 

8 

25 

I 

6 

35 

5 

45 

4 

50 

3 

60 

2 

70 

1 

95 

0 

100 

00 

120 

000 

145 

0000 

175 

i 

23 


WIRING 
1000 


B.  &S. 

GAUGE. 

Per  cent  of 

d.nij}€r€s  tit  top  oj 

Loss. 

2% 

b% 

10* 

~ 

4 

C) 

8 

i  10 

12 

0000 

189000  &44800 

163000 

122250  97800 

81500 

000 

887500  194000 

129150 

9700C 

77500 

64575 

00 

30800015-1000 

102650 

77000;  61600 

51325 

0000 

0 

•244500  122200 

81500 

61100  48900 

40750 

000 

1 

194500  97200 

64800 

48600 

38900 

32400 

00 

2 

154500  77200 

51500 

38600  30900 

25750 

0 

3 

122500  01200 

40820 

30600 

24500 

20415 

0000 

1 

4 

9:000  48500 

3230( 

24250 

18100 

16150 

000 

2 

5 

77000  38500 

25050 

19250 

15400 

12S25 

00 

3 

6 

61000  30400 

20330 

15200 

12200 

10165 

0 

4 

7 

48500,  24200 

16170 

12100 

9700 

7085 

1 

5 

8 

38450  19220 

12815 

9610 

7690 

6410 

2 

6 

9 

30500 

15200 

10150 

7600 

6100 

5075 

3 

7 

10 

24200 

12100 

8065 

6050 

4840 

4030 

4 

8 

11 

19200 

9600 

6400 

4800  3840 

:5200 

k 

9 

12 

15-200 

7600 

5065 

3800  3040 

2530 

6 

10 

13 

12100 

6020 

4015 

301  0!  2410 

2010 

7 

11 

14 

9600 

4800 

3200 

2400 

1920 

it;oo 

8 

13 

15 

7800 

3800 

2535 

1900 

1520 

1270 

9 

13 

10 

6050 

3025 

2015 

1510 

1210 

1010 

10 

14 

4SOO   2400 

1600 

1200 

960 

800 

11 

15 

3800,'  1902 

1270 

950 

700 

635 

12 

16 

8020 

1510 

1005 

755 

605 

500 

13 

2400 

1200'   Him 

600 

480 

400 

14 

1900 

950 

630 

475 

380 

315 

15 

1510 

755 

500 

375 

300 

250 

16 

1195 

600 

400 

300 

240 

200 

24 


Golitmns,  Feet  below. 


1C 

20 

48900 
38750 
30800 

25 

39120 
31000 
24640 

30 

32600 
25830 
20530 

40 

24450 
19400 
15400 

50 

19560 
15500 
12320 

75 

100 

11125 

48500 

38500 

13040 
103:30 
8210 

9780 
7750 
6160 

30550   24450 
24300   19450 
19300   15450 

19560 
15560 
12360 

16300 
12960 
10300 

12220 
9720 
7720 

9780  6550 
7780  5190 
6180  4120 

4890 
3890 
3090 

15300   12250 
12125  I  9700 
9625   7700 

9800 
7760 
6160 

8165 
6460 
5130 

6120 
4850 
3850 

4900  3265 
3880  2585 
3080  2050 

2450 
1940 
1540 

7600 
6050 
4805 

6100 
4850 
3845 

4880 
3880 
3076 

4065 
3230 
2560 

3040 
2420 
1920 

2440 
1940 
1540 

1625 
1895 
1025 

1220 
970 
770 

3800 
3035 
2400 

3050 
2420 
1920 

2440 
1940 
1540 

2030 
1610 
1280 

1520 
1210 
960 

1220 
970 
770 

815 
645 
510 

NO 

185 

1900 
1505 
1200 

1520 
1210 
960 

1220 
965 
770 

1010 
800 
640 

760 
600 

480 

61  0:   405 

480 
385 

9.50 
760 

600 

760 
605 
480 

610 
485 
385 

505 
400 
320 

380 
300 

475 
380 
300 

880 
302 
240 

305 
240 

190 

255 

240 
190 
150 

190 

150 

25 


WIRING 
2000 


B.  &S. 
GAUGE. 

Per  cent  of 
Los<. 

Amperes  at 

top  of 

V 

5% 

10£ 

0000 
000 
00 

1 

1956000 
1550000 
1232000 

o 

3 

4 

6 

8 

1 

978000 
775000 
616000 

652000  !  489000  326000  244500 
5166601387500  258300  194000 
410660J308000J205300  154000 

0000 
000 
00 

0 

1 

8 

978000 
778000 
618000 

489000 
389000 
309000 

326000 
259330 
206000 

244500 
194500 
154500 

163000122200 
P..  9600  97200 
103000  77200 

0000 
000 

0 

1 

2 

3 
4 

5 

490000 
388000 
308000 

245000 
194000 
154000 

163330 
129330 
102660 

122500 
97000 
77000 

81660  61200 
64600  48500 
51300  38500 

00 
0 

1 

3 

4 

R 

6 
8 

244000 
194000 
153800 

122000 
97000 
76900 

81330 
64660 
41260 

61000 
48500 
38450 

40660 
32300 
25630 

30400 
24200 
19220 

o 
3 
4 

6 

8 

9 
10 
11 

122000 
96800 
76800 

61000 
48400 
38400 

40660 
32260 
25600 

30500 
24200 
19200 

20300 
60130 
12800 

15200 
12100 
9600 

5 
6 

7 

9 
10 
11 

12 
13 

14 

60800 
48200 

38400 

30400 
24100 
19200 

20260 
16060 
12800 

15200 
12100 
9600 

10130 
8030 
6400 

7600 
6020 
4800 

8 
9 
10 

12 
13 
14 

15 
16 

30400 
24200 
19200 

15200 
12100 
9600 

10130 
8060 
6400 

7600 
6050 
4800 

5070 
4030 
3200 

3800 
3025 
2400 

11 
12 
13 

14 
15 
16 

15 
16 

15220 

12800 
9600 

7600 
(5040 
4780 

7610 
6040 
4800 

3800 
3020 
2390 

5070 
4020 
3200 

2530 
2010 
1590 

3805 
3020 
2400 

1900 
1510 
1195 

2540 
2010 
1600 

1265 
1005 
795 

1902 
1510 
1200 

950 
755 
600 

26 


TABLE    VII. 
VOLTS. 


Columns,  Feet  beloiv. 


10 

12 

16 

20 

25 

30 

40 

50 

195600 
155000 

mm 

163000 
129150 
102650 

122250 
97000 
77000 

97800 
77500 
61600 

79240 
62000 
49380 

65200 
51665 
41065 

48900 
36750 
30800 

39120 
31000 
24040 

97800 
77800 
61800 

81500 
64800 
51500 

61000 
48600 
38600 

48900 
38900 
30900 

39120 
31120 
24720 

32600 
25930 
20600 

24450 
19450 
15450 

19560 
15560 
12360 

49000 
38800 
30800 

40830 
32300 
26650 

30600 
24250 
19250 

24500 
19400 
15400 

19600 
15520 
13320 

16330 

12930 
10265 

12250 
9700 
7700 

9800 
7760 
6160 

24440 
19400 
15380 

20330 
16170 
12815 

15200 
12100 
9610 

12200 
9700 
7690 

9760 
7760 
6150 

8130 
6465 
5125 

6100 
4850 
3845 

4880 
3880 
3075 

12200 
9680 
7680 

10150 
8065 
6400 

7600 
6050 
4800 

6100 
4840 
3840 

4880 
3870 
3070 

4065 
3225 
2560 

3050 
2420 
1920 

2440 
1935 
1535 

6080 
48->0 
3840 

5065 
4015 
3200 

3800 
3010 
2400 

3040 
2410 
1920 

2430 
1930 
1535 

2025 
1605 
1280 

1520 
1210 
960 

1215 
965 
770 

3040 
2420 
1920 

25:35 
2015 
1600 

1900 
1510 
1200 

1520 
1210 
960 

1215 
970 
770 

1010 
805 
640 

760 
605 

610 

Io20 
1280 
960 

1270 
1005 
800 

950 

755 
600 

760 
605 
480 

610 

760 
605 
480 

630 
500 
400 

475 
375 

TABLE 
ODD    VOLTAGES   AND 


Percent  column. 

50  VOLTS. 

55 

\%  '  2% 

8* 

4^'     5JJ 

1* 

2% 

50-volt  table  
75    'k       '•    . 
110    "        "    

Per  cent  column  . 

1.0    2.0 
2.2    4.5 

4,8.  9.6 

! 

3.0 
6.7 
14.4 

4.0 
9.0 
19.2 

5.0 
12.2 
24.0 

.8 
1.8 
4.0 

"IT? 

8.0 

2.4 
5.6 
12.0 

70  VOLTS. 

75 

1* 

2% 

a* 

4^ 

5* 

1$     2$ 

3* 

50-  volt  table... 
75    "        " 

no  »    "  ;.;:: 

Per  cent  column. 

.5 
1.2 
2.5 

1.0 
5.0 

1.5 
3.4 
7.5 

2.0 
4.6 
10.0 

2  5 

5.'7 
12.5 

.4 
1.0 
2.1 

9 

2.0 
4.2 

1.3 
3.0 

6.3 

!H)  VOLTS. 

95 

1% 

2#     3# 

4% 

5% 

\% 

3* 

3^ 

50-volt  table  

lib  "    "  .*;;.*. 

Per  cent  column. 

.3 
L5 

.6 
1.4 
3.0 

.9 
2  1 
4^5 

1.2 

2.8 
6.0 

1.5 
3.5 

7.5 

.3 

.6 
1.3 

.5 
1.2 

2  7 

.8 
2.0 
4.0 

110  VOLTS. 

115 

W 

2* 

3^ 

4% 

5* 

\% 

2% 

& 

50-volt  table  
75    "        -    . 
110    "        »    .  . 

.2 
A 

1.0 

.4 
.9 
2.0 

1^4 
3.0 

.8 
1.8 
4.0 

1.0 
23 
5.0 

.2 
A 

.9 

A 

.8 
1.8 

6 
1.3 

2  7 

By  means  of  the  above  table,  Tables  I'- 
ll I  can  be  used  for  any  voltage  or  per- 
centage of  loss  with  an  accuracy  within 
the  limits  of  practice. 

For  example,  suppose  the  wiring  is  to  be  for 

90  volts  with  2%  per  cent  loss.     Referring  to 

the  body  of   the  go-volt    section,  we  find  the 

nearest  percentage  of  loss  given  is  2.1$;  then 

28 


VIII. 
PERCENTAGES. 


VOLTS. 

60  VOLTS. 

65  VOLTS. 

3.3 

7.4 
1(5.0 

Dfc 

4.1 
9.3 
20.0 

w 

l'.5 
3.4 

3* 

1.4 
3.1 
6.7 

4.7 
10.0 

2.8 
6.2 
13.4 

5* 

3.5 

7.8 
16.8 

\% 

.6 
1.3 

2.8 

1.2 
2.6 
4.7 

3* 

1.8 
3  9 

8.6 

5^2 
11.5 

5* 

To 

6.5 
13.3 

VOL 

rs. 
& 

80  VOLTS. 

85  VOLTS. 

\% 

2% 

3* 

4% 

5* 

\% 

2% 

3* 

^4* 

5* 

1.8 
4.0 
8.4 

2.2 
5.0 
10.5 

.4 

.8 
1.9 

.8 
1.6 
3.8 

1.2 
2.4 
5.7 

1.6 
3.2 
7.6 

2.0 
4.1 
9.5 

.3 

.8 

i:5 

1.0 
2.3 
5.1 

1.4 
3.1 

6.8 

1.7 
4.0 

8.5 

VOLTS. 

100  VOLTS. 

105  VOLTS. 

4% 

5% 

\% 

2% 

3% 

4% 

5* 

1* 

2* 

3* 

4% 

5* 

1.0 
2.5 
5.4 

1  3 
3.1 

6.7 

.2 
.5 
1.2 

.5 
1.1 
2.4 

3.6 

1.0 
2.2 

4.8 

1.2 

2.8 
6.0 

.2 
.5 
1.1 

.4 
1.0 
2.2 

ila 

3.3 

.9 
2.0 
4.4 

1.2 
2.5 
5.5 

VOL 

4% 
8 

TS. 

1  0 

120  VOLTS. 

125  VOLTS. 

W 

a 

2%     3% 
.3      .5 

7 

8 

\% 

9 

3# 

_. 

4% 

5* 

R 

1.7 

3.6 

2.1 
4.5 

!8 

.8    1.2    1.6    2.0 
1.7   2.5    3.3   4.2 

.4 

.8 

.7'  1.0 
1.5   2.2 

1  4 

3.0 

1.8 
3.8 

following  the  horizontal  and  vertical  columns 
in  turn  we  find  that  this  corresponds  to  the  75- 
volt  table,  using  the  3^  column  of  that  table. 
That  is,  wiring  for  75  volts  with  3$  loss  is  the 
same  as  wiring  for  90  volts  with  2%  loss. 

Similarly,  we  find  that  for  a  loss  of  .6$  with 
no  volts  we  may  use  the  3^  column  of  the  50- 
volt  table. 

29 


TABLE   IX. 

DIMENSIONS     AND     RESISTANCES     OF 
COPPER  WIRE. 


i 

9) 

-T  1 

fe 

J,     £ 

Jl 

| 

3 

a| 

l.J| 

i* 

S  .  E  . 

•2  *  •  -2  8 

.2  s 

a 

•^ 

|X 

|i§r 

is 

fe  aj 
*  S 

2| 

0 

S 

5 

<  "° 

o  a>!£ 

_g 

i 

^ 

fc 

1 

1 

a 

rf 

5 

i 

0000 

.46000 

211600 

166190 

.051288 

.27080 

11.68 

107  21< 

000 

.40964167805 

131790 

.064672 

.34147 

10.405 

85.02^ 

00 

.3648  133079 

104520 

.081549 

.43058 

6.266 

67.43] 

0 

.32495 

105592 

82932 

.1027 

.54223 

8.254 

53.501 

1 

.28930 

83694 

65733 

.129668 

.684627 

7.348 

42.401 

2 

.25763 

66373 

52130 

.1635 

.86328 

6.544 

33.631 

3 

.22942 

52634 

41339 

.2062 

1.08874 

5.827 

26.67C 

4 

.20431 

41742 

32784 

.2599 

1.37237 

5.189 

21.151 

5 

.18194 

33102 

25998 

.32785 

1.731048 

4.621 

16.77? 

6 

.16202 

26250 

20617 

.41343 

2.1829 

4.115 

13.301 

7 

.14428 

20816 

16349 

.5213 

2.7525 

3.665 

8 

.12849 

16509 

12966 

.65737 

3.47091 

3.264 

S.'Sfr 

9 

.11443 

13094 

10284 

.8288 

4.37606 

2.907 

6.63." 

10 

.10189 

10381 

8153 

1.0454 

5.51971 

2.588 

5.26C 

11 

.09074 

8234 

6467 

1.31801 

6.9601 

2.305 

4.172 

12 

.08  81 

6530 

5129 

1.6619 

8.7748 

2.053 

3.  80S 

13 

.07196 

5178 

4067 

2.09588 

11.066 

1.828 

2.618 

14 

.06408 

4107 

8147 

2.6424 

13.87187 

1.628 

2.083 

15 

.05707 

3257 

2558 

3.33205 

17.5993 

1.540 

1.650 

16 

.05082 

2583 

2029 

4.2007 

22.17969 

1.291 

1.309 

17 

.04526 

2048 

1609 

5.299078 

27.9787 

1.150 

1.088 

18 

.04030 

1624 

1276 

6.68258 

35.2836 

1.024 

.822 

19 

.03539 

1252 

984 

8.86814 

45.7670 

.899 

.6346 

20 

.03196 

1021 

802 

10.34128 

54.6020 

.812 

.5176 

TABLE  X. 

EDISON   SYSTEM, 


EDISON   GAUGE. 


'&.. 

Jl* 

Diameter 
in  mils. 

I»N 
$*# 

Maximum 
Amperes. 

CO    1 

1  * 

O   *, 
I 

•3  1 

P   .0 

§  * 

p.    Li 

1  s, 

3 

•  55 

3000. 

12.5 

.0034976 

.00908372 

5 

71 

5000. 

18.3 

.0020986 

.01513924 

8 

90 

8000. 

26.0 

.0013118 

.02422034 

12 

110 

12000. 

35.2 

.0008746 

.03632824 

15 

123 

15000. 

41.6 

.0006997 

.04540984 

20 

142 

20000. 

51.6 

.0005247 

.06054840 

25 

158 

25000. 

61.0 

.0004188 

.07568210 

80 

173 

80000. 

70.0 

.0003498 

.09081666 

35 

187 

85000. 

78.6 

.0002999 

.10595483 

40 

200 

40000. 

86.8 

.0002624 

.12108200 

45 

222 

45000. 

94.9 

.0002332 

.13622748 

50 

224 

50000. 

102.7 

.0002099 

.15135683 

55 

235 

55000. 

110.3 

.0001908 

.16650083 

60 

245 

60000. 

117.7 

.0001749 

.18162452 

65 

255 

65000. 

125.0 

.0001615 

.19677218 

70 

865 

70000. 

132.1 

.0001499 

.21190130 

75 

274 

75000. 

139.1 

.0001399 

.22704321 

80 

283 

80000. 

146.0 

.0001312 

.24217648 

85 

292 

85000. 

152.8 

.0001235 

.25730349 

90 

300 

90000. 

159.5 

.0001166 

.27243450 

95 

308 

95000. 

166.1 

.0001105 

.28758723 

100 

316 

100000. 

172.6 

.0001049 

.30270928 

110 

332 

110000. 

185.4 

.0000954 

.33299060 

120 

346 

120000. 

198.0 

.0000845 

.36326663 

130 

361 

130000. 

210.2 

.0000807 

.39352714 

140 

374 

140000. 

222.2 

.0000750 

.42379665 

150 

387 

150000. 

234.0 

.0000700 

.45406140 

160 

400 

160000. 

245.6 

.0000656 

.48432800 

170 

412 

170000. 

257.0 

.0000617 

.51462206 

180 

424 

180000. 

268.3 

.0000583 

.54488423 

190 

436 

190000. 

279.4 

.0000552 

.57513978 

200 

447 

200000. 

290.4 

.0000525 

.60542734 

TABLE   XI. 

DIFFERENT  WIRE  GAUGES  IN  USE  IN 
THE  UNITED  STATES. 

Dimension*  of  Sizes,  in  Decimal  Ports  of  an  Inch. 


H 

ij 

American, 
or  Brown  & 
Sharpe. 

fa 

11 

QQ 

Washburn  & 
Moen  Mfg.  Co.  ! 
Worcest  V,  Ms.  \ 

Trenton  Iron  \ 
Co.  Trenton, 
N.J. 

§1  . 

s  .?>  «j 

^ 

<3  .« 

Old  English. 

vf 

jl 

^s 

000000 

I 

.46 

00001)0 

00000 

.43 

.45 

00000 

0000 

.&" 

454 

393 

4 

0000 

000 

.40964 

.425 

.362 

.36 

.3586 

000 

00 

.3648 

.38 

.331 

.33 

.3282 

.'.'.'.' 

00 

0 

.32486 

.34 

.807 

.305 

.2994 

0 

1 

.2893 

.3 

.283 

.285 

.2777 

1 

2 

.25763 

.284 

.263 

.265 

.2591 

2 

8  1.22942 

.259 

.244 

.245 

.2401 

8 

4  • 

.  20431 

.238 

.225 

.225 

.223 

4 

5 

.18194 

.22 

.207 

.205 

.2047 

5 

6 

.16202 

.203 

.192 

.19   .1885 

6 

7 

.14428 

.18 

.177 

.175 

.1758 

7 

8 

.12849 

.165 

.162 

.16 

.  1605  .  .  . 

H 

9 

.11443 

.148 

.148 

.145 

.1471  .... 

g 

10 

.  10189 

.134 

.135 

.13 

.1351  

10 

11 

.090742 

.12 

.12 

.  1175 

.1205J  

11 

12 

.080808 

.109 

.105 

.  105 

.  1065 

12 

13 

.071961 

.095 

.092 

.0925 

.0928 

13 

14 

.064084 

.083 

.08 

.08 

.0816 

.083 

14 

15 

.057068 

.072 

.072 

.07 

.0726 

.072 

15 

IB 

.05082 

.065 

.063 

.061 

.0627 

.065 

16 

17 

.045257 

.058 

.054 

.0525 

.0546 

.058 

17 

18 

.040303 

.049 

.047 

.045 

.0478 

.049 

18 

19 

.03589 

.042 

.041 

.04 

.0411 

.04 

19 

20 

.031961 

.035 

.035 

.035 

.0351 

.035 

20 

21 

.028462 

.032 

.032 

.081 

.0321 

.0315  !  21 

22 

.025347 

.028 

.028 

.028 

.029 

.0295 

22 

23 

.022571 

.025 

.025 

.025 

.0261 

.027 

23 

24 

.0201 

.022 

.23 

.0225 

.0231 

.025 

24 

25 

.0179 

.02 

.02 

.02 

.0212 

.023 

25 

26 

.01594 

.018 

.018 

.018 

.0194 

.0205 

26 

27 

.014195 

.016 

.017 

.017 

.0182 

.01875 

27 

28 

.012641 

.014 

.016 

.016 

.017 

.0165 

28 

29 

.011257 

.013 

.015 

.015 

.0163 

.0155 

29 

30 

.010025 

.012 

.014 

.014 

.0156  .01375 

30 

31 

.008928 

.01 

.0185 

.013 

.0146  .01225 

31 

32 

.00795 

.009 

.013 

.012 

.01861.01125 

82 

33 

.00708 

.008 

.011 

.011 

.013  .01025 

33 

34 

.006304 

.007 

.01 

.01 

.0118  .0095 

34 

35 

.005614 

.005 

.0095 

.0095 

.0109  .009 

35 

36 

.005 

.004 

.009 

.009 

.01  .0075 

36 

37 

.004453 

.0085 

.0085 

.0095  .0065 

37 

38 

.003965 

.008 

.008 

.009 

.00575 

38 

39 

.003531 

.0075 

.0075 

.0083 

.005 

88 

40 

.003144 

.007 

.007 

.0078 

.0045 

40 

32 


TABLE   XII. 
BARE   AND   INSULATED   WIRES. 


APPROXIMATE  No.  OF  FEET  PER  POUND. 

1 

3 

"z  r^\ 

S 

9 

c8 

o 

-  .§ 

'S5.g       si 

5 

03 

,1 

GQ 

55 

l£ 

s    ^ 

* 

$ 

£ 

. 

."ti 

•|| 

3 

_ 

;~ 

PQ 

£ 

S'g          5"* 

fl^ 

.S'S 

^ 

•5 

ti 

o^- 

i£i     2£ 

32 

il 

« 

2 

d 

a 

fc 

5 

O          S 

tf 

4 

* 

0000 

1. 

1. 

1.5 

1.56 

000         1.5 

1.4 

1.9 

1.97 

00 

2. 

1.7 

2  34 

2.49 

0 

2.75 

2.5 

2.1        2.5 

2.9 

2.7 

3.13 

1 

3.20 

3.25 

3.66 

3.26 

3.95 

0 

4. 

4.25 

3^37     4^5       4.54 

4.27 

4.99 

3 

5. 

5.25 

3.88     5.5 

5.6 

5. 

6.29 

4 
5 

6.25 

8. 

6.25 

8. 

4.68     6.75     7.1 
5  64     8.33     8.7 

5.9 

7.4 

7.93 
10. 

6 

9.50 

10. 

6.67    10. 

10.75 

9. 

12.61 

7 

12.5 

12.25 

8.73    12  5 

13. 

10. 

15.9 

8 

14.5 

14. 

12.42    13.75 

15.6 

12.5 

20.05 

9 

17. 

16.3 

18. 

15.3 

25.28 

10 

20. 

17.9      19.75 

22.7 

18. 

31.88 

11 

26. 

27. 

40.20 

12 

32. 

27.21    25. 

33.3 

24. 

50.69 

13 

38.5 

63.91 

14 

45. 

36.9     50. 

49. 

80.59 

15 

59. 

101.63 

16 

70. 

53.8 

71.4 

128.14 

17 

85. 

161,59 

18 

90. 

72.1 

93. 

203.76 

19 

111. 

264.26 

20 

110. 

82.5 

133. 

324.00 

33 


TABLE  XIII. 

LIMITING   CURRENTS  FOR  INTERIOR 
WIRING. 

(KENNELLY.) 

Applies  to  insulated  copper  house-wires  of  98  per 
cent  conductivity,  carrying  steady  currents,  and 
encased  in  wooden  moulding.  The  rule  followed  is 
that  the  temperature  elevation  of  any  wire  shall  not, 
with  the  proposed  current,  exceed  18°  F.  or  10°  C. 


Amperes. 

Number  in 
B.  &  S.  1 

Diameter 
in  inches. 

Circular 
Mills. 

Amperes. 

Number  in 
B.&S. 

Diameter 
in  inches. 

Circular 
Mills. 

1000 

1.47 

2160900 

61 

3 

.2294 

52634 

900 

1.37 

1876900 

52 

4 

.2043 

41742 

800 

1.27 

1612900 

43 

5 

.1819 

33102 

700 

1.16 

1345600 

36 

6 

.1620 

26244 

600 

1.049 

1100401 

30 

7 

.1442 

20822 

550 

.988 

976144 

25 

8 

.1284 

16512 

500 

.928 

861184 

22 

9 

.1144 

13110 

475 

.897 

804609 

18 

10 

.1019 

10381 

450 

.865 

748225 

15 

11 

.0907 

8226 

425 

.832 

692224 

12 

12 

.0808 

6528 

400 

.800 

640000 

10.5 

13 

.0719 

5184 

375 

.766 

586756 

9.0 

14 

.0641 

4110 

350 

.732 

535824 

7.25 

15 

.0571 

3260 

325 

.697 

485809 

6.00 

16 

.0508 

2581 

300 

.060 

435600 

5.50 

17 

.0452 

2044 

275 

.623 

388129 

4.00 

18 

.0403 

1624 

250 

.585 

342225 

3.25 

19 

.0359 

1253 

225 

.545 

297025 

2.75 

20 

.0319 

1024 

200 

.504 

254016 

2.25 

21 

.0285 

820 

174 

0000 

.460 

211(500 

2.00 

22 

.0253 

626 

147 

000 

.4096 

167805 

1.75 

23 

.0226 

510 

124 

00 

.3648 

133079 

1.50 

24 

.0201 

404 

103 

0 

.3-249 

105592 

1.25 

25 

.0179 

320 

87 

1 

.2893 

83694 

1.00 

26 

.0159 

254 

73 

2 

.2576 

66373 

34 


TABLE  XIV. 

CURRENTS  AND   CORRESPONDING  ELEVA- 
TIONS OF  TEMPERATURE  OF  OPEN-AIR 
CONDUCTORS  IN  CALM  WEATHER. 

(BLACK  INSULATION.) 
(Compiled  from  Kennelly's  Experiments.) 


Gauge 
B.  &  S. 

9°F. 

18°  F. 

36°  F. 

72°  F. 

0000 

250 

345 

480 

680 

000 

210 

295 

405 

565 

00 

175 

245 

350 

480 

0 

145 

205 

290 

400 

1 

125 

175 

250 

345 

2 

105 

150 

210 

290 

3 

90 

125 

175 

240 

4 

75 

110 

150 

210 

5 

65 

90 

125 

175 

6 

55 

75 

105 

145 

7 

50 

65 

95 

125 

8 

40 

55 

80 

110 

10 

30 

45 

60 

80 

12 

25 

30 

45 

60 

14 

20 

25 

35 

45 

16 

15 

20 

25   ' 

35 

Rise 


in  temperature  at   top  of  columns,  amperes 
below. 


35 


m  ?o  i-     oooso      i-i  o?  so      "*  LO  «o      j>xoi 

1-1   1-1   1-1  1-1   T-l   ?J  C>    71   ?t  OJ   C»   ?J  ?<    r*    ?{ 


S-*  rf« 
O«O 


l^     ?°S3     £?ioi 


co  i-  oo 

oio^-H      oicort*      »o  as  i-     OOO5O 

0-    - 

ocoooo 

GOOOQO        000000        000000        000000 

CO  Tin 

5Ol>OO        OiOi-H        OZSO^        O«Ol> 

0,    ,. 

0~« 

6 

O»OIOI 

OI  OI  OJ        OI  OI  OI       OI  OI  OI       OI  Oi  OI 

pa 

Or-«!N        SO-^lO       COI>QO       OiO»-i 

36 


8 

6 

3 

fc-  -     * 

d  ..  „      -  -  _ 

d-  -      -  ^  ^      ^  *  - 

8 

OOOOOO       000000       000000 

00 

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d-  -.      -  *  -      -  -.  - 

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55'  * 

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TABLE  XVI. 
KESISTANCES. 


Material. 

Approximate 
Comparative 
Resistances. 

Resistance  of  100 
Feet  of  No.  20 
(B  &  S.)  Wire, 
in  Ohms. 

Copper  

1 

1.016 

Aluminum 

1  8 

1  82 

Zinc  

3  4 

3.45 

Platinum  
Iron 

5.5 
6 

8.81 
6  03 

Nickel    

7.6 

7.68 

Tin 

8 

8.12 

Lead 

12 

12  1 

German-silver  .  .  . 
Antimony  

13 
21 

13.6 

Ferro-nickel  
Mercury     

50 

58 

50.8 

Bismuth  
Sulphuric  acid... 

80 
2.6xlO« 

•••••• 

GAUGES   (B.  &   S.)  OF  DIFFERENT  WIRES 
FUSED   BY   100   AMPERES. 

(PREECE.) 

Copper, No.  17 

Aluminum "     15 

Platinum "13 

German-silver,  ....  "13 

Platinoid, "12 

Iron, "     10 

Tin, .  "      6 

Lead,   .......  "      6 

Tin-lead  alloy,  ....  "       5 


TABLE   XVII. 

WEIGHT   AND   RESISTANCE    OF   GAL  VAN 
IZED  IEON  WIRE  PER  MILE. 

(ROEBLINQ.) 


Gauge. 
B.  &S. 

Weight 
per 
Mile. 

Resist- 
ance. 
Ohms. 

Gauge. 

B.  &  :  S. 

Weight 
per 
Mile. 

Resist- 
ance. 
Ohms. 

6 

8 
9 
10 

550 
470 
385 
330 
268 

10 
12.1 
14.1 
16.4 
20 

11 

12 
14 
16 

216 
170 
100 
62 

20 
32.7 
52.8 
91.6 

TABLE   XVIII. 

TABLE  OF  RESISTANCES  OF  18  PER  CENT 
GERMAN-SILVER  WIRE. 

(AMERICAN  ELECTRICAL  WORKS.) 


B.  &S. 
Gauge. 

Ohms 
per 
1000ft. 

Ohms 
perlb.  1 

B.  &S. 
Gauge. 

Ohms 
per 

1000  ft. 

Ohms 
per  Ib. 

No.  8 
9 
10 

11.772 
11.832 
18.72 

.23598 
.37494 
.  59652 

No.  25 
26 
27 

606.312 
764.586 
964.134 

626.31 
995.958 
1583.622 

11 
12 

13 

23.598 
29.754 
37.512 

.94842 
1.50786 
2.39778 

28 
29 
30 

1215.750 
1533.00 
1933.038 

2518.075 
4004.082 
6368.356 

14 
15 
16 

47.304 
59.65^ 
75.222 

3.8124  i 
6.0624 
9.639 

31 
32 
33 

2437.  23G 
3073.77 
3875.616 

10119.978 
16096.356 
25589.628 

17 
18 
19 

94.842 
119.61 
155.106 

15.327 
24.3702 
40.9896 

34 
35 
36 

4888.494 
6163.974 
7770.816 

40712.76 
64729.87 

102876.  -482 

20 
21 
22 

190.188 
239.814 
302.382 

61.614 
97.974 
155.772 

37 

38 
39 

9797.166 
12357.198 
15570.828 

163524.78 
257764.68 
409546.8 

23 
24 

381.33 
480.834 

247.734 
393.93 

40 

19653.57 

652024.62 

39 


WHITE   CEDAR    POLES. 

(ELECTRICAL  SUPPLY  Co.)  . 


xa 

£  00 

j 

5«3 

S^-oS 

1*0  ** 

o,^u 

§"S  eS 

^^2  S 

Size. 

?3  tX  cc 

^«w 

Size. 

2.S?  w 

Xq_, 

Oj  aj'O 

5^1 

p,0-  o 

>>  s 
^^§ 

g^oS 

p-l 

<* 

£ 

^« 

25',  top  4" 

25',    5" 

160 
200 

170 
150 

35',  top  7' 
35',  u  8' 

650 

-,oo 

90 

85 

25',    6" 

250 

120 

35',  "  9' 

850 

70 

25',    7" 

325 

100 

40',  "  6' 

800 

80 

25',    8" 

475 

75 

140',  "  7' 

900 

75 

25',   9" 

550 

60 

40',  "  8' 

950 

70 

30',    5" 

300 

110 

45',  "  6' 

1000 

65 

30',    6" 

350 

90 

45',  "  7' 

1200 

55 

30',    7" 

450 

75 

50',  "  6' 

1400 

52 

30',    8" 

600 

55 

50',  "  7' 

1500 

40 

30',    9" 

700 

45 

55',  "  7' 

1600 

37 

35',   6" 

550 

100 

60',  "  7' 

1700 

35 

Green  chestnut  poles  weigh  about  50  per  cent  more 
than  the  above  figures. 
Poles  40  ft.  long  and  over  require  two  cars. 


DIMENSIONS  OF    CROSS   ARMS. 

Regular  size,  3^  inches  x  4^  inches,  i-J- 
inch  holes. 

Special  size,  4  inches  x  5  inches,  i^-inch 
holes. 

2-pin,  3  feet  long;  4-pin,  4  or  5  feet 
long;  6-pin,  6  feet  long. 


40 


CANDLE-POWEK   OF   ARC    LAMPS. 

(ANTWERP  ELECTRICAL  EXPOSITION.) 


Amperes. 

a 

'o 
> 

Maximum 
C.P. 

Horizontal 
C.P. 

Upper  Hemi- 
sphere. 
Mean  C.  P. 

Lower  Hemi- 
sphere. 
Mean  C.  P. 

Mean  C.  P. 

3 

1 

4 

37.2 

390 

74 

17 

119 

136 

157 

0 

46.2 

1090 

168 

63 

298 

361 

259 

6.8 

46 

1240 

240 

65 

320 

385 

313 

8 

46 

1550 

334 

70 

385 

454 

350 

10 

45.5 

2070 

421 

102 

640 

750 

491 

LIGHT    CUT    OFF   BY    GLOBES. 

Clear  glass 10  per  cent 

Light  ground  glass 30     "      " 

Heavy  ground  glass 45  to  50     "      " 

Strong  opals.  ...    50  to  60     "      " 


An  incandescent  lamp  gives  off  from  £ 
to  TV  the  heat  of  an  equivalent  gas-jet. 

An  arc  lamp  gives  off  from  -£•$  to  ¥V  as 
much  heat  as  gas-jets  producing  an  equal 
light. 

A  5-foot  (16  c.  p.)  gas-jet  vitiates  as  much 
air  as  four  men. 


1 

0 

Derivation 

1 

X 

2 
& 

:  -5-  ampere 
illion  ohms 
illionth  ohm 

t  H-  ohm 
ousandth  amp 

T5 

a 

X 

y 

1 

lomb  -=-  volt 
illionth  farad 

:  X  ampere 
t  X  ampere  X  1 

t  x  colomb 

s 

oSS 

of: 

S 

gg 

"33 

o 

<5 

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>•£" 

K* 

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a|| 

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JO 

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ad 
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g 

9 

fc 

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oil 

11 

8 

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43 


TOOLS   REQUIRED 

The  following-named  tools  will  probably  be  re- 
quired in  constructing  a  plant  for  city  or  commercial 
lighting  : 

(DAVIS.) 


Article. 

Size. 

Cost 
about 

Stubs'  pliers,  plain  

Sin. 

$2.00 
3.00 
8.00 
2.25 
2.50 
4.80 
6.00 
6.00 
.95 
1.50 
1.25 
3.50 
2.60 
.90 
.75 
6.00 
2.00 
2.40 
12.00 
20.00 
1.00 
3.50 
2.10 
1.50 
3.00 
.80 
1.25 
.30 

Climbers  and  straps          

Pulley  -block  and  ecc.  clamp  

)     To 
vNo  3 

Come-along  and  strap 

Splicing  clamps 

\  B.&S. 

Linemen's  tool-bag  and  strap    .   ... 

Soldering  furnace 

Gasoline  blow  -pipes  .                    ... 

Soldering  coppers 

21b. 
8ft. 
7ft. 
8ft. 
7ft. 
10  Ib. 

Pole  -hole  shovels           

Pole-hole  spoon   regular 

Octagon  digging-  bars  

Tamping-bars 

Crowbar      

Pick  -axe 

Cant-hook 

4ft. 
16ft. 
6ft. 

Pike-poles          

Pole-supporter 

Comb,  pay-out  reel  and  straps  

Nail-hammer 

1  Ib. 
6  in. 
12  in. 
26  in. 
10  in. 
Sin. 
12  in. 
12  in. 

Linemen's  broad  hatchets  
Drawing-knives 

Hand-saw  

Ratchet-brace  bits 

Screw-drivers  

Wrench 

Bastard  file    .  . 

44 


APPROXIMATE   LIST   OF   SUPPLIES 

REQUIRED    IS    INSTALLING    15  CITY    LAMPfe  AND   20  COM- 
MERCIAL LAMPS  ON  A  FIVE-MILE  CIRCUIT,    SETTING 
POLES   132  FEET  APART. 

(DAVIS.) 


Articles. 

Size  or 
Diameter 

Price 
about. 

Quan- 
tity. 

Electric-light  poles  
Electric-light  poles 

30ft.,  6  in. 
35  ft    7  in 

$2.40each 
4  15 

180 

Electric-light  poles  ...... 
Cross  arms,  4-pin.  . 

40ft.,  Tin. 
4ft. 

5.50 
.30 

40 
200 

Painted  oak  pins   

Hin. 

.02 

800 

Oak  pins  and  bolts  
Irou  break-arms 

Hin. 

.0? 

24 
25 

Lag-screws  and  washers. 
Glass  insulators  D  G 

*  X  7  in. 

.04 
74 

400 

850 

Pole  steps  

g.  X  8  in. 

'.05 

2500 

Guy  stranded  cable  
Cross-arm  brace  &  bolts. 
Line  wire  ... 

fin. 
6  BS 

.071b. 
.20each 
125  00  mi 

SOOlbs. 
40 
6  miles 

MATERIAL   REQUIRED   FOR    CONNECTING 
IN   LAMPS. 

(DAVIS.) 


Sleet-proof  pulleys 

fO  75  each 

30 

Street-lamp  cleats,  iron.. 

.25    " 

15 

Arc-lamp  cordage  
Suspension  cable 

fin. 
i  in 

1.25hdft 
02ift 

25 

3000ft 

Hard-rubber  tube  
Soft-rubber  tubing  
Arc  cut-out  

f  X  I  in. 
fin. 

l.SOlb. 
.20ft. 
3  50  each 

5  IDS. 
200ft. 
20 

Porcelain  insulators  and 
screws  

2  40  hd. 

400 

Oak  brackets  and  spikes 

2  50    " 

150 

45 


HORSE  POWER  OF  ENGINES. 

Commercial  horse  power  rating  of  sim- 
ple high  speed,  single  or  double  acting 
engines,  based  on  40  pounds  mean  indi- 
cated pressure  with  80  pounds  initial  pres- 
sure. 

D  —  diameter  in  inches  ; 
S  =  stroke       "      " 
N  =  number  of  revolutions  per  minute. 

80  pounds  boiler  pressure, 

H   P  * 

H-P-= 


90  pounds  boiler  pressure, 


.. 

5600 

100  pounds  boiler  pressure, 


.. 

5000 

EXAMPLE.     Diameter   cylinder,  10  in.  ; 
stroke,  10  in.  ;  revolutions  per  minute,  300. 

H.  P.  =  0£JfJg)_?LI0  x  3°°  =      6 

6300 

at  80  pounds  pressure. 
Similarly, 

H.  P.  =  53.5  at    90  pounds  pressure. 
H.P.  =  60     ••    100      « 
46 


HORSE  POWER  OF  BOILERS. 

The  following  commercial  rating  of 
boilers  is  based  on  heating  surface,  and  on 
80  pounds  pressure  and  40  pounds  of  water 
per  indicated  horse  power. 

D  —  diameter  of  boiler  in  inches  ; 
d  =         "         "   tubes    "       " 
L  —  length      "       "       "    feet; 
/=  "       "        "    inches, 

;/  =  number    "       " 

HORIZONTAL  TUBULAR  BOILERS. 

(To  200  H.  P.) 

CASE  I.     L(D  +  nd)  is  less  than  50000. 
H  P  _L(D+nd) 
62 

CASE  2.    L(D  +  nd}  is  between  50000  and 
70000. 

H  P=^  +  '"0 

55 

CASE  3.     L(D  4-  nd)  is  over  70000. 


H  P  _ 

50 

EXAMPLE.  Diameter  boiler,  48  in.;  length 
tubes,  14  ft.  ;  diameter  tubes,  3  in.  ;  num- 
ber tubes,  52. 


_ 
47 


UPRIGHT  TUBULAR  BOILERS— FULL 
LENGTH  TUBES. 

(To  60  H.  P.) 

l(D  -h  nd) 


H.P.  = 


620 


EXAMPLE.  Diameter,  36  in.  ;  length 
tubes,  51  in. ;  diameter  tubes,  2  in.  ;  num- 
ber tubes,  77. 

H  p  _.  5U36  +  77  x  2)  =  i 
620  5' 


UPRIGHT     TUBULAR    BOILERS.  —  SUB- 
MERGED  TUBES. 

(To  60  H.  P.) 

l(D  4-  nd) 


H.P.  = 


500 


EXAMPLE.  Diameter  boiler,  24  in.;  length 
tubes,  30  in. ;  diameter  tubes,  2  in. ;  num- 
ber tubes,  31. 

TT  p  _  30(24  +  3i  x  2)  _ 
i~i.  i  .  —  —  5» 

500 

NOTE. — In" the  above  formulae  for  boilers,  allowance 
has  been  made  for  the  greater  efficiency  of  heating 
surface  exposed  to  direct  radiation. 
48 


RULES  FOR  CALCULATING  THE 

SPEED  OF  PULLEYS 

AND  GEARS. 

To  find  the  REVOLUTIONS  of  a  DRIVEN 

shaft,  multiply  the  diameter  of  the  driving 
pulley  by  its  speed  in  revolutions  and  di- 
vide by  the  diameter  of  the  driven  pulley. 
EXAMPLE.  Engine  pulley,  42  in.;  en- 
gine revolutions,  240;  dynamo  pulley, 
8  in. 


_                          42  x  240 
Dynamo  rev.  = ~ =  1260. 


To   find   the  DIAMETER   of   a  DRIVEN 

pulley,  multiply  the  diameter  of  the  driv- 
ing pulley  by  its  speed  in  revolutions  and 
divide  by  the  required  speed  of  the  driven 
shaft. 

EXAMPLE.  Engine  pulley,  66  in.;  en- 
gine revolutions,  303 ;  dynamo  speed, 
2000  rev. 


66  x  303 
Diam.  dynamo  pulley  = =  10  in. 

49 


To  find  the  DIAMETER  of  a  DRIVING 

pulley,  multiply  the  diameter  of  the  driven 
pulley  by  its  revolutions  arid  divide  by  the 
revolutions  of  the  driving  shaft. 

EXAMPLE.     Dynamo  revolutions,  1500; 
dynamo  pulley,  10  in.;  counter  speed,  600 


....  10  x  1500 

Diam.  counter-driver  = — —  =  25  in. 

600 

Where  a  COUNTER  is  to  be  used,  the 
problem  is  in  two  parts,  the  countershaft 
being  first  considered  the  driven  and  next 
the  driver,  or  vice  versa.  The  above  rules 
can  similarly  be  extended  to  any  number 
of  intermediate  shafts  or  counters. 

EXAMPLE.  Shafting  pulley,  48  in.; 
shafting  revolutions,  120;  counter  driven 
pulley,  12  in.;  dynamo  pulley,  8  in.;  dy- 
namo revolutions,  1500.  Required  coun- 
ter driving  pulley. 

48  x  1 20 
Counter  rev.  = =  480. 

8  x  1 500 
Diam.  counter  driver  = g^—  =  25  in. 

For  GEARS,  substitute  the  number  of 
teeth  in  the  above  rules  for  the  diameter 
in  inches. 

50 


INSTRUCTIONS      FOR 

AND    LINEMEN. 

(JAS.  I.    AVER,) 

When  cutting  wire,  grip  the  line  with 
the  cutting  jaws  of  pliers  and  move  up  and 
down  at  right  angles  with  the  wire  two  or 
three  times,  so  that  you  cut  the  insulation 
part  of  the  way  round  on  both  sides  ;  then 
hold  your  pliers  firmly  bend  the  wire  once 
or  twice  up  and  down  with  your  left  hand, 
and  the  wire  will  break.  Never  try  to 
break  the  wire  by  twisting  your  pliers, 
unless  you  first  move  the  line  out  of  the 
cutting  jaws.  There  is  no  excuse  fof 
nicks  in  the  cutting  jaws  of  Stubs'  pliers, 
and  careful  linemen  rarely  have  it  happen. 

In  stripping  the  ends  of  wire  to  make 
a  connection,  always  cut  along  the  wire 
towards  the  end,  in  much  the  same  man- 
ner as  if  whittling  a  stick.  Never  cut 
round  the  wire  with  the  edge  of  the  knife 
or  pliers,  excepting  when  cutting  the  wire. 

In  making  joints,  be  careful  never  to  let 
the  cutting  jaws  or  edge  of  your  tools 
"score  "  the  wire.  If  you  do,  don't  cover 
it  up,  but  make  a  new  joint. 


After  a  joint  is  made  with  not  less  than 
four  turns  each  side  of  the  connectors, 
dip  or  moisten  with  acid.  If  you  are  on 
the  ground,  dip  the  joint  in  melted  solder 
and  hold  it  there  a  few  seconds,  to  thor- 
oughly heat  the  joint,  then  take  it  out. 
If  well  "tinned,"  dip  it  in  water  to  remove 
any  acid  which  may  be  on  the  ends  of  the 
wire  near  the  insulation. 

If  where  you  cannot  dip  the  joint,  but 
have  to  use  the  ladle,  pour  the  solder 
frequently  over  the  joint  until  it  leaves  a 
thin  smooth  coating  on  the  wire.  It  is 
not  properly  done  if  the  solder  is  in  lumps 
or  in  a  thick  layer. 

If  you  are  obliged  to  use  a  "  blow-pot," 
hold  the  joint  in  the  flame  until  the  solder 
will  easily  melt  when  held  against  the  wire 
after  the  flame  is  removed.  When  this  is 
accomplished,  apply  the  solder  with  the 
flame  and  not  before. 

Solder  is  put  on  the  joint  to  keep  it 
from  corroding,  thereby  insuring  good 
contact  where  the  two  wires  come  to- 
gether, and  is  of  no  use  if  not  well  applied. 

After  the  joint  is  well  cleaned  of  acid 
after  being  soldered,  paint  it  thoroughly 
with  insulating  compound,  then  cover 
with  a  layer  of  tape,  which  you  will  start 
on  one  side  of  the  joint  against  the  insu- 
lation of  the  wire  but  not  over  it.  Have 
52 


the  first  layer  cover  the  joint  and  bare 
wire  only.  When  this  is  done  paint  it ; 
then  start  back  over  the  joint  and  tape 
until  you  have  run  over  the  line  insulation 
about  two  inches,  then  wrap  two  layers, 
painting  each  when  done. 

In  wrapping  tape,  cover  what  you  have 
laid  half,  or  lap  one  half.  After  four 
layers  are  on  paint  the  whole  thoroughly. 

Whenever  you  find  a  break  in  the  insu- 
lation on  the  line  anywhere,  paint  it  first, 
then  tape  and  paint  it.  Don't  forget  this. 

No  joints  should  be  permitted  to  be 
made  and  left  without  being  soldered. 

Never  fail  to  put  in  "  drip-loops  "  in  line 
where  entering  building. 

In  all  electrical  work,  remember  where 
insulation  is  desired  it  can  never  be  too 
good,  or  when  contact  is  desired  you  can 
never  make  it  too  good  or  strong.  Always 
avoid  temporary  work. 

In  making  house  connections,  where 
wires  enter  building,  have  not  less  than 
six  inches  clearance  from  cornices  of  walls. 
All  wiring  running  over  cornices  or  other 
building  projections  should  be  protected 
with  rubber  tubing  thoroughly  taped  and 
painted  at  the  ends.  Never  let  a  wire, 
however  well  protected,  come  in  contact 
with  the  outside  portion  of  the  building. 
53 


In  placing  tubing  on  wire,  carefully 
paint  and  tape  at  the  upper  end,  leaving 
the  lower  end  open,  so  that  moisture  can 
escape  if  it  should  get  hi; 

In  placing  converters  and  making  con- 
nections to  same,  you  should  always  leave 
the  line  connection  where  you  branch  to 
be  made  after  all  other  work  is  completed. 
The  primary  fuses  at  the  converter  must 
be  left  out  until  the  final  line  connections 
are  completed* 

In  making  connections  to  constant 
potential  (alternating  or  5oo-volt)  circuits, 
always  finish  one  connection  before  break- 
ing the  insulation  on  the  other  line.  Re- 
member this  :  that  you  must  have  but  one 
wire  or  joint  bare  at  a  time  when  working 
on  the  lines. 

After  completing  a  converter  connection 
and  before  closing  line  connections,  care- 
fully paint  the  entire  outfit  (except  glass 
insulators)  with  insulating  paint. 

See  that  all  wires  leading  out  of  con- 
verters and  out  of  fuse-boxes  are  well 
taped  and  painted  where  they  leave  the 
converter;  and  all  converters  must  be 
placed  as  far  from  doors,  balconies,  win- 
dows, and  other  openings,  as  possible,  and 
sufficiently  high  above  ground  or  roof,  to 
prevent  accidental  contact;  in  other  words, 
out  of  reach. 

54 


All  secondary  wires  from  the  converter 
to  house  should  be  as  well  insulated  and 
protected  from  grounds  as  if  carrying  high- 
pressure  currents. 

In  plugging  brick  or  stone  buildings, 
paint  the  plugs  with  insulating  compound 
before  driving  them. 

All  supports  for  converters  and  fuse- 
boxes  placed  on  buildings  must  be  well 
painted  with  insulating  paint. 

In  renewing  fuses  of  secondary  wires, 
be  sure  that  the  binding-post  screws  which 
hold  the  line  wires  are  firmly  set.  Fuses 
are  frequently  blown  by  loose  line  con- 
ductors. 

When  primary  fuses  are  blown,  examine 
converter  for  short  circuit  or  leakage  be- 
fore replacing  them. 

When  main- line  secondary  fuses  are 
blown,  test  with  the  current  on  both  legs 
for  ground,  if  circuit  is  being  used.  If  not, 
you  may  test  with  magneto  bells,  first  re- 
moving both  fuses  on  main  block  and 
testing  wires  to  lamps  only. 

In  placing  fuses  in  secondary  circuits, 
always  open  the  switch  on  the  branch 
before  fused,  or  turn  the  lamps  "off"  at 
sockets  before  replacing  fuse. 

When  replacing  fuses,  always  test  for 
55 


grounds  or  short  circuits  on  lines  where 
fuses  are  blown. 

Use  your  fuse  test  wire  for  all  tests  on 
secondaries,  if  testing  with  current.  Where 
grounds  are  found,  unless  cleared  by  you, 
the  branch  grounded  must  be  left  cut  out. 

When  placing  guard  wires  on  street 
crossings,  always  use  iron  pins  and  glass 
insulators  to  attach  both  ends  of  guard 
wires  to.  Never  tie  on  cross  arm  or  pole, 
as  in  stormy  weather,  when  they  should 
be  of  use,  they  will  thus  become  danger- 
ous. 

In  working  on  lines  all  circuits  must  at 
all  times  be  regarded  as  alive  and  grounded. 
With  many  wires,  some  of  which  may  be 
carrying  heavy  currents,  some  using  ground 
returns,  the  line  you  are  on  may  "come 
alive  "  any  time.  Be  careful. 

See  that  all  tools  are  securely  fastened 
in  your  belt  when  working  on  pole  or  lad- 
der, and  in  handling  lines  and  wires  on 
poles  have  a  proper  regard  for  the  safety 
of  those  passing  beneath. 

When  working  on  poles  always  use  your 
safety  belt,  as  well  as  other  desirable 
safety  devices.  It  takes  but  little  time  to 
make  yourself  safe,  and  many  weeks  to 
mend  a  broken  bone. 
56 


Never  lay  tools  down  when  above  the 
ground. 

In  putting  in  jumpers,  be  careful  that  the 
loop  of  jumper  does  not  lie  on  wiresN^elow 
and  thus  make  a  cross  possible  if  the  in- 
sulation does  not  hold. 

Always  run  wires  in  straight  parallel 
lines,  and  make  square  turns  where  possi- 
ble. Twelve  inches  between  wires  is  the 
proper  space  for  arc-lighting  circuits,  where 
practicable. 

Never  fasten  a  cut-out  box  against  the 
wall.  Always  place  glass  or  porcelain 
knobs  between  the  box  and  wall. 

In  tying  in,  never  draw  the  tie  wire  so 
as  to  bend  a  kink  in  the  line  or  cut  through 
the  insulation  with  the  tie.  A  tie  will 
properly  hold  the  wire  in  place  without 
drawing  it  so  tight  as  to  do  either. 

In  using  pulley-blocks  on  the  line,  avoid 
the  use  of  "  come-alongs  "  when  possible, 
by  taking  a  series  of  half  hitches,  or  mak- 
ing a  "  noose  wrap  "  with  a  small  line  on 
the  wire  to  hook  the  block  to.  If  you  do 
use  "come-alongs,"  see  that  you  do  not 
score,  cut,  or  kink  the  wire,  and  always 
paint  and  tape  broken  insulation. 

Groundmen  are  especially  cautioned  to 
watch  the  line  in  "  paying  out  "  and  pre- 
vent "  kinking."  Should  a  short  "kink" 
57 


get  pulled  into  the  line,  cut  it  out  rather 
than  take  the  risk  of  breaking. 

Never  use  porcelain  knobs  where  they 
will  be  exposed  to  moisture  or  the  weather, 
and  never  use  them  anywhere  else  if  glass 
can  possibly  be  substituted. 

Porcelain  knob  circuit  breakers  may  be 
used  where  necessary,  provided  not  more 
than  two  lamps  are  on  the  loop.  In  mak- 
ing them,  paint  and  insulate  with  tape  the 
joints  in  connecting  wire  or  loop. 

In  removing  lamps  ordered  out,  always 
close  the  loop  at  the  line  where  it  was 
originally  cut  in  and  remove  all  dead  wire. 
Never  leave  dead  or  unnecessary  wire  in 
circuit. 

Always  use  iron  pins  on  arms  where 
wires  turn  a  corner  or  leave  the  line. 

Never  screw  an  insulator  on  an  iron  pin 
or  bracket  very  tightly,  nor  without  first 
putting  inside  the  glass  a  strip  of  paper 
folded  twice  or  three  times.  This  will  pre- 
vent the  glass  being  broken,  as  iron  ex- 
pands with  heat  nearly  twice  as  rapidly  as 
glass,  and  unless  there  is  room  enough  the 
difference  in  temperature  between  winter 
and  summer  will  burst  insulators  in  sum- 
mer that  were  placed  in  winter. 


RULES  AND  REQUIREMENTS 

FOR   THE   INSTALLATION    OF 

ELECTRIC  LIGHT  AND  POWER, 

AS 

REVISED  AND  CODIFIED 

BY    TH  E 

UNDERWRITERS'  INTERNATIONAL  ELECTRIC 
ASSOCIATION.* 


CLASS   A. 
CENTRAL  STATIONS. 

FOR    LIGHT    OR    POWER. 

These  Rules  also  apply  to  Dynamo  Rooms 
in  Isolated  Plants,  connected  ivith  or  de- 
tached from  buildings  used  for  other  pur- 
poses ;  also  to  all  varieties  of  apparatus 
therein  of  both  high  and  low  potential. 

I.   GENERATORS— 

a.  Must  be  located  in  a  dry  place. 

b.  Must  be  insulated  on   floors  or  base 
frames,  which  must  be  kept  rilled  to  pre- 
vent absorption  of  moisture,  and  also  kept 
clean  and  dry. 

*  See  Appendix  for  definitions  of  the  word  AP- 
PROVED and  rules  for  the  introduction  of  Automatic 
Fire  Alarm  Systems. 

59 


c.  Must  never  be  placed  in  a  room  where 
any  hazardous  process  is  carried  on,  nor  in 
places  where  they  would   be  exposed  to 
inflammable  gases  or  flyings  or  combusti- 
ble material. 

d.  Must  each  be  provided  with  a  water- 
proof covering. 

2.  CAKE    AND    ATTENDANCE.— A    com- 
petent man  must  be  kept  on  duty  in  the 
room  where  generators  are  operating. 

Oily  waste  must  be  kept    in   approved 
metal  cans  and  removed  daily. 

3.  CONDUCTORS — from  generators, 
switchboards,    rheostats   or   other  instru- 
ments, and  thence  to  outside  lines — 

a.  Must  be  in  plain  sight,  and  readily 
accessible. 

b.  Must  be  wholly  on  non-combustible 
insulators,  such  as  glass  or  porcelain. 

c.  Must  be  separated  from  contact  with 
floors,  partitions,  or  walls  through  which 
they  may  pass  by  non-combustible  insulat- 
ing tubes,  such  as  glass  or  porcelain. 

d.  Must  be  kept  rigidly  so  far  apart  that 
they  cannot  come  in  contact. 

e.  Must  be  covered  with  non-inflamma- 
ble  insulating  material  sufficient  to  pre- 
vent accidental  contact,  except  that  "  bus 
bars  "  may  be  made  of  bare  metal. 

60 


f.  Must  have  ample  carrying  capacity, 
to  prevent  heating.  (See  Capacity  of 
Wires  Table.) 

4.  SWITCHBOARDS— 

a.  Must  be  so  placed  as  to  reduce  to  a 
minimum  the  danger  of   communicating 
fire  to  adjacent  combustible  material. 

b.  Must    be    accessible   from    all   sides 
when  the  connections  are  on  the  back ;  or 
may  be  placed  against  a  brick  or  stone 
wall   when   the  wiring  is  entirely  on  the 
face. 

c.  Must  be  kept  free  from  moisture. 

d.  Must   be   made   of    non-combustible 
material,    or   of   hard    wood    in   skeleton 
form,    filled     to    prevent     absorption    of 
moisture. 

e.  Bus  bars  must  be  equipped  in  accord- 
ance with  Rule  3  for  placing  conductors. 

5.  RESISTANCE  BOXES  AND  EQUALIZERS— 

a.  Must    be    equipped   with    metal    or 
other  non-combustible  frames. 

b.  Must  be  placed  on  the  switchboard, 
or,  if  not  thereon,  at  a  distance  of  a  foot 
from  combustible  material,   or  separated 
therefrom  by  a  non-inflammable,  non-ab- 
sorptive, insulating  material. 

6.  LIGHTNING   ARRESTERS— 

«.  Must  be  attached    to   each    side  of 
61 


every  overhead  circuit  connected  with  the 
station. 

b.  Must  be  mounted  on  non-combustible 
bases  in  plain  sight  on  the  switchboard,  or 
in  an  equally  accessible  place,  away  from 
combustible  material. 

c.  Must  be  connected  with   at  least  two 
"  earths "  by  separate  wires,    not  smaller 
than   No.  6   B.  &  S.,  which   must   not  be 
connected  to  any  pipe  within  the  building. 

d.  Must  be   so  constructed    as   not   to 
maintain  an   arc  after   the  discharge  has 
passed. 

7.    TESTING. 

a.  All    series  and    alternating   circuits 
must  be  tested  every  two  hours  while  in 
operation  to  discover  any  leakage  to  earth, 
abnormal    in   view   of   the    potential    and 
method  of  operation. 

b.  All  multiple-arc  low-potential  systems 
(300  volts  or  less)  must  be  provided  with 
an  indicating  or  detective  device,  readily 
attachable,  to  afford  easy  means  of  testing 
where  the  station  operates  continuously. 

c.  Data  obtained  from  all  tests  must  be 
preserved   for   examination   by   insurance 
inspectors. 

These  rules  on  testing  to  be  applied  at 
such  places  as  may  be  designated  by  the 
association  having  jurisdiction. 
62 


8.  MOTORS- 

a.  Must  be  wired  under  the  same  pre- 
cautions as  with    a   current  of   the  same 
volume   and  potential  for  lighting.     The 
motor  and   resistance  box  must   be   pro- 
tected by  a  double-pole  cut-out  and  con- 
trolled by  a  double-pole  switch. 

b.  Must  be  thoroughly  insulated,  mount- 
ed on  rilled  dry  wood,  be  raised  at  least 
eight  inches  above  the  surrounding  floor, 
be  provided  with  pans  to  prevent  oil  from 
soaking  into  the  floor,  and  must  be  kept 
clean. 

c.  Must  be   covered  with  a  waterproof 
cover  when  not   in   use,  and,   if   deemed 
necessary  by  the  Inspector,  be  enclosed  in 
an  approved  case. 

9.  RESISTANCE   BOXES— 

a.  Must    be   equipped    with    metal    or 
other  non-combustible  frames. 

b.  Must  be  placed  on  the  switchboard  or 
at  a  distance  of  a  foot  from  combustible 
material,  or  separated  therefrom  by  a  non- 
inflammable,    non  -  absorptive,    insulating 
material. 


63 


CLASS    B. 

ARC  (SERIES)   SYSTEMS. 
OVER  300  VOLTS. 

10.    OUTSIDE  CONDUCTORS.— All  outside 
overhead  conductors  (including  services) — 

a.  Must  be  covered  with  some  approved 
insulating    material,    not   easily    abraded, 
firmly  secured  to  properly  insulated  and 
substantially  built  supports,  all  tie  wires 
having  an  insulation  equal  to  that  of  the 
conductors  they  confine. 

b.  Must  be  so  placed  that  moisture  can- 
not form  a  cross-connection  between  them, 
not  less  than  a  foot  apart,  and  not  in  con- 
tact with  any  substance  other  than  their 
insulating  supports. 

c.  Must  be  at  least  seven  feet  above  the 
highest  point  of  flat  roofs  and  at  least  one 
foot  above  the  ridge  of  pitched  roofs  over 
which   they    pass  or  to   which   they   are 
attached. 

d.  Must  be  protected  by  dead  insulated 
guard  irons  or  wires  from   possibility  of 
contact  with   other  conducting  wires   or 
substances   to   which   current   may    leak. 

64 


Special  precautions  of  this  kind  must  be 
taken  where  sharp  angles  occur  or  where 
any  wires  might  possibly  come  in  contact 
with  electric  light  or  power  wires. 

e.  Must  be  provided  with  petticoat  insu- 
lators of  glass  or  porcelain.  Porcelain 
knobs  or  cleats  and  rubber  hooks  will  not 
be  approved. 

f.  Must  be  so  spliced  or  joined  as  to  be 
both  mechanically  and  electrically  secure 
without  solder.  The  joints  must  then  be 
soldered  to  insure  preservation,  and  cov- 
ered with  an  insulation  equal  to  that  on 
the  conductors. 

11.  SERVICE  BLOCKS— 

a.  Must   be   covered   over  their  entire 
surface  with  at  least  two  coats  of  water- 
proof paint. 

b.  Telegraph, telephone,  and  similar  wires 
must  not  be  placed  on  the  same  cross-arm 
with  electric  light  or  power  wires. 

12.  ALL  INTERIOR  CONDUCTORS— 

a.  Must  be  covered  where  they  enter 
buildings  from  outside  terminal  insulators 
to  and  through  the  walls  with  extra  water- 
proof insulation,  and  must  have  drip  loops 
outside.  The  hole  through  which  the 
conductor  passes  must  be  bushed  with 
waterproof  and  non-combustible  insulat- 
ing tube  or  hard  rubber  tube,  slanting  up- 
65 


ward  toward  the  inside.  The  tube  must 
be  sealed  with  tape,  thoroughly  painted, 
and  securing  the  tube  to  the  wire. 

b.  Must  be  arranged  to  enter  and  leave 
the    building  through   a   double   contact 
service  switch,  which  will  effectually  close 
the  main  circuit  and  disconnect  the  inte- 
rior wires  when  it   is  turned  "off."     The 
switch  must  be  so  constructed  that  it  shall 
be  automatic  in  its  action,  not  stopping 
between  points  when  started,  and  prevent 
an  arc  between  the  points  under  all  cir- 
cumstances ;    it  must  indicate  on  inspec- 
tion whether  the  current  be  "on"  or  "off," 
and   be    mounted    in   a    non-combustible 
case,  and    kept   free   from    moisture   and 
easy  of  access  to  police  or  firemen. 

c.  Must  be  always  in  plain   sight,  and 
never  encased,  except  when   required  by 
the  Inspector. 

d.  Must  be  covered  in  all  cases  with  an 
approved  non-combustible   material    that 
will  adhere  to  the  wire,  not  fray  by  fric- 
tion, and  bear   a  temperature  of  150°  F. 
without  softening. 

e.  Must  be  supported  on  glass  or  porce- 
lain insulators,  and  kept  rigidly  at  least 
eight  inches  from  each  other,  except  with- 
in the  structure  of  lamps  or   on    hanger 
boards,  cut-out  boxes,  or  the  like,  where 
less  distance  is  necessary. 

66 


f.  Must  be  separated  from  contact  with 
walls,  floors,  timbers,  or  partitions  through 
which  they  may  pass  by  non-combustible 
insulating  tube  or  hard-rubber  tube. 

g.  Must  be  so  spliced  or  joined  as  to  be 
both  mechanically  and  electrically  secure 
without  solder.     They  must  then  be  sol- 
dered to  insure  preservation,  and  covered 
with  an  insulation  equal  to  that   on  the 
conductors. 

13.    AEG  LAMPS— in  every  case— 

a.  Must  be  carefully  isolated   from  in- 
flammable material. 

b.  Must  be  provided  at  all  times  with  a 
glass  globe  surrounding  the  arc,  securely 
fastened  upon  a  closed  base.     No  broken 
or  cracked  globes  to  be  used. 

c.  Must  be  provided  with  an  approved 
hand   switch,   also   an   automatic   switch, 
that  will   shunt   the  current   around   the 
carbons  should  they  fail   to  feed  properly. 

d.  Must  be  provided  with   reliable  stops 
to  prevent  carbons  from  falling  out  in  case 
the  clamps  become  loose. 

e.  Must  be  carefully  insulated  from  the 
circuit  in  all  their  exposed  parts. 

f.  Must  be  provided  with  a  wire  netting 
around  the  globe  and  an  approved  spark 
arrester  above  to  prevent  escape  of  sparks, 
melted  copper   or  carbon,  where   readily 

67 


inflammable  material  is  in  the  vicinity  of 
the  lamps.  It  is  recommended  that  plain 
carbons,  not  copper-plated,  be  used  for 
lamps  in  such  places. 

g.  Hanger-boards  must  be  so  constructed 
that  all  wires  and  current-carrying  devices 
thereon  shall  be  exposed  to  view,  and  thor- 
oughly insulated  by  being  mounted  on  a 
water-proof,  non-combustible  substance. 
All  switches  attached  to  the  same  must  be 
so  constructed  that  they  shall  be  automatic 
in  their  action,  not  stopping  between 
points  when  started,  and  preventing  an  arc 
between  points  under  all  circumstances. 

14.  INCANDESCENT  LAMPS  IN  SERIES  CIR- 
CUITS HAVING  A  MAXIMUM  POTENTIAL 
OF  300  VOLTS  OR  OVER— 

a.  Must  be  governed  by  the  same  rules 
as  for  arc   lights,    and   each    series   lamp 
provided  with   an    approved   hand-spring 
switch  and  automatic  cut-out. 

b.  Must  have  each  lamp  suspended  from 
a  hanger-board  by  means  of  a  rigid  tube. 

c.  No     electro  -  magnetic    device     for 
switches  and  no  system  of  multiple-series 
or  series-multiple  lighting  will  be  approved. 

d.  Under  no   circumstances  can   series 
lamps  be  attached  to  gas  fixtures. 

68 


CLASS  C. 

INCANDESCENT  (LOW-PRESSURE)  SYSTEMS. 
300   VOLTS    OR    LESS. 

15.  OUTSIDE    OVERHEAD   CONDUCTORS— 

a.  Must  be  erected  in  accordance  with 
the  rules  for  arc  (series)  circuit  conductors. 

b.  Must  be  separated  not   less  than   12 
inches,  and  be  provided  with  an  approved 
fusible  cut-out  that  will  cut  off  the  entire 
current  as  near  as  possible  to  the  entrance 
to  the  building  and  inside  the  walls. 

16.  UNDERGROUND    CONDUCTORS— 

a.  Must  be  protected  against  moisture 
and  mechanical  injury,  and  be  removed  at 
least  two  feet  from  combustible  material 
when  brought  into  a  building  but  not  con- 
nected with  the  interior  conductors. 

b.  Must  have  a  switch  and  a  cut-out  for 
each  wire  between  the  underground  con- 
ductors and  the  interior  wiring  when  the 
two  parts  of  the  wiring  are  connected. 

These  switches  and  fuses  must  be  placed 
as  near  as  possible  to  the  end  of  the  un- 
derground conduit  and  connected  there- 
with by  specially  insulated  conductors, 
kept  apart  not  less  than  two  and  a  half 
inches. 

c.  Must  not  be  so  arranged  as  to  shunt 
the   current   through    a   building   aiound 
any  catch-box. 


INSIDE   WIRING— GENEfcAL   RULES. 

17.  At  the  entrance  of  every  building 
there  shall  be  an  approved  switch  placed 
in  the  service  conductors  by  which  the 
current  may  be  entirely  cut  off. 

18.  CONDUCTORS— 

a.  Must   have   an    approved   insulating 
covering,  and  must  not  be  of  sizes  smaller 
than  No.  14  B.  &  S.,  No.  16  B.  W.  G.,  or 
No.  4  E.  S.  G.,  except  that,  in  conduit  in- 
stalled under  Rule  22,  No.  16  B.  &  S.,  No. 
18  B.  W.  G.,  or  No.  4  E.   S.   G.  may   be 
used. 

b.  Must    be     protected    when     passing 
through  FLOORS,  or  through  walls,  parti- 
tions, timbers,  etc.,  in  places  liable  to  be 
exposed  to  dampness  by  waterproof,  non- 
combustible,  insulating  tubes,  such  as  glass 
or  porcelain. 

Must  be  protected  when  passing  through 
walls,  partitions,  timbers,  etc.,  in  places 
not  liable  to  be  exposed  to  dampness  by 
approved  insulating  bushings  specially 
made  for  the  purpose. 

c.  Must  be  kept  free  from  contact  with 
gas,   water,  or   other    metallic   piping,   or 
any  other  conductors  or  conducting  ma- 
terial which  they  may  cross  (except  high 
potential  conductors)  by  some  continuous 
and  firmly  fixed  non-conductor  creating  a 

70 


separation  of  at  least  one  inch.  Devia- 
tions from  this  rule  may  sometimes  be 
allowed  by  special  permission.  \-^  ^ 

d.  Must  be  so  placed  in  crossing  high 
potential  conductors  that  there  shall  be  a 
space  of  at  least  one  foot  at  all  points  be- 
tween the  high  and  low  tension  conduc- 
tors. 

e.  Must  be  so  placed  in  wet  places  that 
an  air-space  will  be  left  between  conduc- 
tors and  pipes  in  crossing,  and  the  former 
must  be  run  in  such  a  way  that  they  can- 
not come  in  contact  with  the  pipe  acci- 
dentally.    Wires  should   be   run   over  all 
pipes  upon  which  condensed  moisture  is 
likely  to  gather,  or  which  by  leaking  might 
cause  trouble  on  a  circuit. 

INSIDE   WIRING— SPECIAL    RULES. 
19.  WIRING   NOT   ENCASED  IN  MOULDING 
OR   APPROVED    CONDUIT— 

a.  Must  be   supported  wholly  on    non- 
combustible  insulators,  constructed  so  as 
to  prevent  the  insulating  coverings  of  the 
wire  from  coming  in  contact  with  other 
substances  than  the  insulating  supports. 

b.  Must  be  so  arranged   that  wires  of 
opposite  polarity,  with  a  difference  of  po- 
tential  of   150  volts  or  less,  will   be  kept 
apart  at  least  two  and  one  half  inches. 

c.  Must    have   the  above   distance   in- 


creased  proportionately  where  a  higher 
voltage  is  used  unless  they  are  encased  in 
moulding  or  approved  conduit. 

d.  Must  not  be  laid  in  plaster,  cement, 
or  similar  finish. 

e.  Must  never  be  fastened  with  staples. 

IN  UNFINISHED  LOFTS,  BETWEEN  FLOOR 
AND  CEILINGS,  IN  PARTITIONS  AND  OTHER 
CONCEALED  PLACES— 

f.  Must  have  at  least  one  inch  clear  air- 
space surrounding  them. 

g.  Must   be   at  least  ten    inches   apart 
when  possible,  and  should  be  run  singly 
on  separate  timbers  or  studding. 

h.  Wires  run  as  above  immediately  un- 
der roofs,  in  proximity  to  water  tanks  or 
pipes,  will  be  considered  as  exposed  to 
moisture. 

/.  Wires  must  not  be  fished  for  any 
great  distance,  and  only  in  places  where 
the  Inspector  can  satisfy  himself  that  the 
above  rules  have  been  complied  with. 

j.  Twin  wires  must  never  be  employed 
in  this  class  of  concealed  work. 
20.  MOULDINGS— 

a.  Must   never    be    used    in    concealed 
work  or  in  damp  places. 

b.  Must  have  at  least  two  coats  of  water- 
proof   paint    or   be   impregnated   with   a 
moisture  repellant. 

72 


c.  Must  be  made  of  two  pieces,  a  back- 
ing and  capping,  so  constructed  as  to 
thoroughly  encase  the  wire,  and  maintain 
a  distance  of  one  half-inch  between  con- 
ductors of  opposite  polarity,  and  afford 
suitable  protection  from  abrasion. 

21.  SPECIAL    WIRING, 

In  breweries,  packing-houses,  stables, 
dye-houses,  paper  and  pulp  mills,  or  other 
buildings  specially  liable  to  moisture  or 
acid,  or  other  fumes  liable  to  injure  the 
wires  or  insulation,  except  where  used  for 
pendants,  conductors — 

a.  Must  be  separated  at  least  six  inches. 

b.  Must  be  provided  with  an  approved 
waterproof  covering. 

c.  Must  be  carefully  put  up. 

d.  Must  be  supported   by  glass  or  por- 
celain insulators.     No  switches  or  fusible 
cut-outs  will  be  allowed  where  exposed  to 
inflammable  gases  or  dust,  or  to  flyings  of 
combustible  material. 

e.  Must    be    protected    when    passing 
through  floors,  walls,   partitions,  timbers, 
etc.,  by  waterproof,  non-combustible,  in- 
sulating tubes,  such  as  glass  or  porcelain. 

22.  INTERIOR    CONDUITS*— 

a.   Must  be  continuous  from  one  junc- 

*  The  object  of  a  tube  or  conduit  is  to  facilitate  the 
insertion  or  extraction  of  the  conductors,  to  protect 
them  from  mechanical  injury,  and,  as  far  as  possible, 

73 


tion  box  to  another,  or  to  fixtures,  and 
must  be  of  material  that  will  resist  the 
fusion  of  the  wire  or  wires  they  contain, 
without  igniting  the  conduit. 

b.  Must  not  be  of  such  material  or  con- 
struction that  the  insulation  of  the  con- 
ducto'r  will  ultimately  be  injured    or   de- 
stroyed by  the  elements  of  the  composi- 
tion. 

c.  Must  be  first  installed  as  a  complete 
conduit      system,     without      conductors, 
strings,  or  anything  for   the    purpose  of 
drawing  in  the  conductors,  and  the  con- 
ductors then  to  be  pushed  or  fished   in. 
The  conductors  must  not  be  placed  in  po- 
sition until  all  mechanical  work   on   the 
building  has  been,  as  far  as  possible,  com- 
pleted. 

d.  Must  not  be  so  placed  as  to  be  sub- 
ject to  mechanical  injury  by  saws,  chisels, 
or  nails. 

e.  Must    not   be  supplied   with   a   twin 
conductor,  or  two  separate  conductors,  in 
a  single  tube. 

f.  Must  have  all  ends  closed  with  good 
adhesive  material,  either  at  junction  boxes 
or  elsewhere,  whether  such  ends  are  con- 


from  moisture.  Tubes  or  conduits  are  to  be  considered 
merely  as  raceways,  and  are  not  to  be  relied  on  for  in- 
sulation between  wire  and  wire  or  between  the  wire 
and  the  ground. 

74 


cealed  or  exposed.     Joints  must  be  made 
air-tight  and  moisture-proof. 

g.  Conduits  must  extend  at  least  one 
inch  beyond  the  finished  surface  of  walls 
or  ceilings  until  the  mortar  or  other  simi- 
lar material  be  entirely  dry,  when  the  pro- 
jection may  be  reduced  to  half  an  inch. 
23.  DOUBLE  POLE  SAFETY  CUT-OUTS— 

a.  Must  be  in  plain  sight  or  enclosed  in 
an  approved  box,  readily  accessible. 

b.  Must  be  placed  at  every  point  where 
a  change  is  made  in  the  size  of  the  wire 
(unless  the  cut-out  in  the  larger  wire  will 
protect  the  smaller). 

c.  Must  be  supported  on  bases  of  non- 
combustible,     insulating,    moisture-proof 
material. 

d.  Must   be   supplied   with    a   plug   (or 
other  device  for  enclosing  the  fusible  strip 
or  wire)  made  of  incombustible  and  moist- 
ure-proof   material,   and    so    constructed 
that  an  arc  cannot  be   maintained  across 
its  terminals  by  the  fusing  of  the  metal. 

e.  Must  be  so  placed  that  on  any  com- 
bination fixture  no  group  of  lamps  requir- 
ing a  current  of  six  amperes  or  more  shall 
be  ultimately  dependent  upon  one  cut-out. 
Special  permission  may  be  given  /;/  writ- 
ing by  the   Inspector  for  departure  from 
this  rule  in  case  of  large  chandeliers. 

/.  All  cut-out  blocks  must  be  stamped 
75 


with  their  maximum  safe  carrying  capacity 
in  amperes,  and  when  installed  must  be 
marked  with  the  current  they  are  intended 
to  carry. 

24.  SAFETY   FUSES— 

a.  Must   all    be   stamped   or   otherwise 
marked  with  the  number  of  amperes  they 
will  carry  indefinitely  without  melting. 

b.  Must   have    fusible   wires    or    strips 
(where  the  plug  or  equivalent  device  is 
not  used),  with  contact  surfaces  or  tips  of 
harder  metal,  soldered  or  otherwise,  hav- 
ing perfect  electrical  connection  with  the 
fusible  part  of  the  strip. 

c.  Must  all  be  so  proportioned  to  the 
conductors  they  are  intended  to   protect 
that  they  will  melt  before  the  maximum 
safe  carrying  capacity  of  the  wire  is  ex- 
ceeded. 

25.  TABLE    OF   CAPACITY    OF   WIRES— 

It  must  be  clearly  understood  that  the 
size  of  the  fuse  depends  upon  the  size  of 
the  smallest  conductor  it  protects,  and  not 
upon  the  amount  of  current  to  be  used  on 
the  circuit.  Below  is  a  table  showing  the 
safe  carrying  capacity  of  conductors  of 
different  sizes  in  Birmingham,  Brown  & 
Sharpe,  and  Edison  gauges,  which  must 
be  followed  in  the  placing  of  interior  con- 
ductors: 

76 


BROWN  &  SHARPS. 

BIRM 

[NGHAM.      E 

(NoUge 

Amperes. 

GNogC 

Amperes. 

oooo   .  . 

..-.175 

oooo.  . 

i75 

ooo.    . 

i45 

ooo.. 

150 

oo.  .  . 

120 

00.  . 

130 

0.  .. 

100 

o.  . 

no 

95 

I.  . 

95 

2  .  . 

70 

2.  . 

85 

3   • 

..   ..  60 

3  • 

75 

4   • 

50 

4-- 

65 

5   • 

45 

5  • 

60 

6... 

35 

6.. 

50 

7   • 

3° 

7-- 

45 

8.. 

25 

8.. 

35 

0     . 

....   20 

0.  . 

30 

2.  . 

15 

2.  . 

.     .     .  .     20 

4    •  • 

.     ...     10 

4   • 

15 

6  . 

5 

6.. 

IO 

8.. 

3 

8.. 

5 

20.  . 

3 

Amp's. 


200  .... 

....175 

180.... 

..  .160 

140  

....135 

no  

no 

00.... 

••••  95 

80.... 

...  85 

65  ... 

••••  75 

50  .... 

....  60 

40... 

-  ...  50 

30  .... 

....  40 

25... 

••••  35 

20  

....  30 

12 

....  20 

8  ... 

....  15 

5---- 

10 

3.... 

....  5 

2.  .  .  . 

....  3 

26.  SWITCHES— 

a.  Must  be  mounted  on  moisture-proof 
and  non-combustible  bases,  such  as  slate 
or  porcelain. 

b.  Must  be  double-pole   when   the   cir- 
cuits which  they  control  supply  more  than 
six  16  candle-power  lamps,  or  their  equiv- 
alent. 

c.  Must  have  a  firm  and  secure  contact, 
must    make   and    break    readily,  and    not 
stop  when  motion  has  once  been  imparted 
by  the  handle. 

d.  Must  have  carrying  capacity  sufficient 
to  prevent  heating. 

77 


e.  Must  be  placed  in  dry,  accessible 
places,  and  be  grouped  as  far  as  possible, 
being  mounted — when  practicable — upon 
slate  or  equally  non-combustible  back- 
boards. Jack-knife  switches,  whether  pro- 
vided with  friction  or  swing  stops,  must 
be  so  placed  that  gravity  will  tend  to  open 
rather  than  close  the  switch. 

27.  FIXTURE   WORK. 

a.  In   all    cases   where   conductors   are 
concealed  within  or  attached   to  gas  fix- 
tures, the  latter  must  be  insulated   from 
the  gas-pipe  system    of  the   building   by 
means  of  approved  joints.     The  insulating 
material  used  in  such  joints  must  be  of  a 
substance  not  affected  by  gas,  and  that  will 
not  shrink  or  crack  by  variation  in  tem- 
perature.      Insulating    joints    with     soft 
rubber  in  their  construction  will    not  be 
approved. 

b.  Supply  conductors,  and  especially  the 
splices  to  fixture  wires,  must  be  kept  clear 
of  the   grounded    part   of  gas-pipes,  and 
where  shells  are  used  the  latter  must  be 
constructed   in  a  manner  affording  suffi- 
cient area  to  allow  this  requirement. 

c.  When  fixtures  are  wired   outside,  the 
conductors  must  be  so  secured  as  not  to 
be  cut  or  abraded  by  the  pressure  of  the 
fastenings  or  motion  of  the  fixture. 

78 


d.  All  conductors  for  fixture  work  must 
have  a  waterproof  insulation  that  is  dura- 
ble and  not  easily  abraded,  and  must  not 
in  any  case  be  smaller  than  No.  18  B.  &  S., 
No.  20  B.  W.  G.,  or  No.  2  E.  S.  G. 

e.  All    burrs   or  fins   must   be  removed 
before  the  conductors  are  drawn    into  a 
fixture. 

f.  The  tendency  to  condensation  within 
the  pipes  should  be  guarded  against  by 
sealing  the  upper  end  of  the  fixture. 

g.  No  combination  fixture  in  which  the 
conductors  are  concealed  in  a  space  less 
than  one-fourth  inch  between  the  inside 
pipe  and  the  outside  casing  will  be  ap- 
proved. 

//.  Each  fixture  must  be  tested  for  "  con- 
tacts "  between  conductors  and  fixtures, 
for  "short  circuits,"  and  for  ground  con- 
nections before  the  fixture  is  connected  to 
its  supply  conductors. 

/.  Ceiling  blocks  of  fixtures  should  be 
made  of  insulating  material ;  if  not,  the 
wires  in  passing  through  the  plate  must 
be  surrounded  with  hard-rubber  tubing. 

28.    ARC  LIGHTS  ON  LOW  POTENTIAL  CIR- 
CUITS— 

a.  Must  be  supplied  by  branch  conduct- 
ors not  smaller  than  No.  12  B.  &  S.  gauge. 
79 


b.  Must  be  connected  with  main   con- 
ductors only  through  double-pole  cut-outs. 

c.  Must   only   be    furnished    with    such 
resistances  or  regulators   as  are  enclosed 
in  non-combustible  material,  such  resist- 
ances being  treated  as  stoves. 

Incandescent  lamps   must  not  be  used 
for  resistance  devices. 

d.  Must   be   supplied   with  globes   and 
protected  as  in  the  case  of  arc  lights  on 
high-potential  circuits. 

29.  ELECTRIC  GAS  LIGHTING. 

Where  electric  gas-lighting  is  to  be  used 
on  the  same  fixture  with  the  electric  light — 

a.  No  part  of  the  gas-piping  or  fixture 
shall  be  in  electrical  connection  with  the 
gas-lighting  circuit. 

b.  The   wires   used   with    the    fixtures 
must  have  a  non-inflammable  insulation, 
or,  where  concealed  between  the  pipe  and 
shell   of  the    fixture,  the  insulation  must 
be  such  as  requited  for  fixture  wiring  for 
the  electric  light. 

c.  The  whole  installation  must  test  free 
from  "grounds." 

d.  The  two  installations  must  test  per- 
fectly  free   from    connection    with    each 
other. 

80 


\o  *t>°*  <£ 

V  V,     J'^Qfi 

30.  SOCKETS— 

V(^    <S^    ^tf\. 

rt.  No  portion  of  the  lamp  socket  ex- 
posed to  contact  with  outside  objects  must 
be  allowed  to  come  into  electrical  contact 
with  either  of  the  conductors. 

b.  In  rooms  where  inflammable  gases 
may  exist,  or  where  the  atmosphere  is 
damp,  the  incandescent  lamp  and  socket 
should  be  enclosed  in  a  vapor-tight  globe. 

31.  FLEXIBLE  CORD— 

a.  Must  be  made  of    conductors,   each 
surrounded    with    a    moisture-proof   and 
non-inflammable  layer,  and  further  insu- 
lated   from   each   other  by  a  mechanical 
separator  of  carbonizable  material.     Each 
of  these  conductors  must  be  composed  of 
several  strands. 

b.  Must    not    sustain    more    than  one 
light  not  exceeding  50  candle-power. 

c.  Must   not   be  used,  except  for  pen- 
dants,  wiring   of    fixtures,   and    portable 
lamps  or  motors. 

d.  Must    not  be  used  in  show-windows. 

e.  Must    be    protected    by    insulating 
bushings  where  the  cord  enters  the  socket, 
The  ends  of   the  cord  must  be  taped  to 
prevent  fraying  of  the  covering. 

f.  Must  be  so  suspended  that  the    en- 

81 


tire  weight  of  the  socket  and  lamp  will  be 
borne  by  knots  under  the  bushing  in  the 
socket,  and  above  the  point  where  the 
cord  comes  through  the  ceiling  block  or 
rosette,  in  order  that  the  strain  may  be 
taken  from  the  joints  and  binding  screws. 
g.  Must  be  equipped  with  keyless 
sockets  as  far  as  practicable,  and  be  con- 
trolled by  wall  switches. 


CLASS  D. 
ALTERNATING    SYSTEMS.  —  CONVERTERS 

OR  TRANSFORMERS. 
32.  CONVERTERS— 

a.  Must  not    be    placed  inside    of  any 
building,  except  the  Central  Station,  unless 
by  special  permission  of  the  Underwriters 
having  jurisdiction. 

b.  Must  not  be  placed  in  any  but  me- 
tallic or  other  non-combustible  cases. 

c.  Must  not  be  attached  to  the  outside 
walls  of  buildings,  unless  separated  there- 
from by  substantial  insulating  supports. 

IN  THOSE  CASES  WHERE  IT  MAY  NOT  BE 
POSSIBLE  TO  EXCLUDE  THE  CONVERT- 
ERS AND  PRIMARY  WIRES  ENTIRELY 
FROM  THE  BUILDING,  THE  FOLLOWING 

PRECAUTIONS    MUST    BE    STRICTLY   OB- 
SERVED— 

33.  Converters  must  be  located  at  a 
point  as  near  as  possible  to  that  at  which 
the  primary  wires  enter  the  building,  and 
must  be  placed  in  a  room  or  vault  con- 
structed of,  or  lined  with,  fire-resisting 
material,  and  used  only  for  the  purpose. 
They  must  be  effectually  insulated  from 
83 


the  ground,  and  the  room  in  which  they 
are  placed  be  practically  air-tight,  except 
that  it  shall  be  thoroughly  ventilated  to 
the  outdoor  air,  if  possible,  through  a  chim- 
ney or  flue. 

34.  PRIMARY  CONDUCTORS— 

a.  Must  each  be  heavily  insulated  with 
a  coating  of  moisture-proof  material  from 
the  point  of  entrance  to  the  transformer, 
and,  in  addition,  must  be  so  covered  and 
protected  that  mechanical  injury  to  them 
or  contact  with  them   shall  be  practically 
impossible. 

b.  Must  each  be  furnished,  if   within  a 
building,  with  a  switch  and  a  fusible  cut- 
out where  the  wires  enter  the  building,  or 
where  they  leave  the   main   line,  on   the 
pole   or  in   the  conduit.     These  switches 
should  be  enclosed  in  secure  and  fireproof 
boxes  preferably  outside  the  building. 

c.  Must  be  kept  apart  at  least  ten  inches, 
and  at  the  same  distance  from  all  other 
conducting  bodies  when  inside  a  building. 

35.  SECONDARY  CONDUCTORS— 

a.   Must  be  installed  according  to  the 
rules  for  "  Low-Potential  Systems." 


84 


CLASS   E. 
ELECTRIC    RAILWAYS. 

36.  All  rules  pertaining  to  arc-light  wires 
and  stations  shall  apply  (so  far  as  possible) 
to  street-railway  power  stations  and  their 
conductors  in  connection  with  them. 

37.  POWER  STATIONS— 

a.  Must  be  equipped  in  each  circuit  as  it 
leaves  the  station  with  an  approved  auto- 
matic "  breaker"  or  other  device  that  will 
immediately  cut  off  the  current  in  case  the 
trolley  wires  become  grounded.  This  de- 
vice must  be  mounted  on  a  fire-proof  base 
and  in  full  view  and  reach  of  the  attendant. 

38.  TROLLEY  WIRES— 

a.  Must  be  no  smaller  than  No.  o  B.  & 
S.  copper  or  No.  4  B.  &  S.  silicon  bronze, 
and  must  readily  stand  the  strain  put  upon 
them  when  in  use. 

b.  Must  be  well  insulated  from  their  sup- 
ports, and,  in  case  of  the  side  or  double- 
pole  construction,  the  supports  shall  'also 
be  insulated  from  the  poles  immediately 
outside  of  the  trolley  wire. 

c.  Must    be    capable    of    being    discon. 
nected   at   the   povver-house,  or  of  being 
divided   into  sections,  so  that,  in  case  of 
fire  on  the  railway  route,  the  current  may 

85 


be  shut  off  from  the  particular  section  and 
not  interfere  with  the  work  of  the  firemen. 
This  rule  also  applies  to  feeders. 

d.  Must  be  safely  protected  against  con- 
tact with  all  other  conductors. 

39.  CAR  WIRING— 

a.  Must  be  always  run  out'  of  reach  of 
the  passengers,  and  must  be  ifisulated:with 
a  waterproof  insulation. 

46.  LIGHTING   AND    POWER    FROM  RAIL- 
WAY WIRES'— 

a\  Must  not  be' permitted' under  any  pre-~ 
tence  in  the  same  circuit  with  trolley  wires; 
with  a  ground  return,  nor  shall  the  same 
dynamo  be  used  for  both  purposes,  except 
in  street  railway  cars,  electric  car  houses, 
and  their  power  stations. 

41.  CAR  HOUSES— 

Must  have  special  cut-outs  located  at  a 
proper  distance  outside  so  that  all  circuits 
within  any  car  house  can  be  cut  out  at  one 
point. 

42.  GROUND  RETURN  WIRES. 

Where  ground  return  is  used  it  must  be 
so  arranged  that  no  difference  of  potential 
will  exist  greater  than  five  volts  to  50  feet, 
or  50  volts  to  the  mile,  between  any  two 
points  in  the  earth  or  pipes  therein. 
86 


CLASS    F. 

43.  STOEAGE  OR  PRIMARY  BATTERIES. 

a.  When  current  for  light  and  power  is 
taken  from  primary  or  secondary  batteries 
the  same  general  regulations  must  be  ob- 
served as   apply  to  similar  apparatus  fed 
from   dynamo  generators  developing  the 
same  difference  of  potential. 

b.  All     secondary    batteries     must     be 
mounted  on  approved  insulators. 

c.  Special  attention   is  directed   to  the 
rules    (page   73)    for    rooms    where  acid 
fumes  exist. 

d.  The  use  of  any  metal  liable  to  corro- 
sion must  be   avoided  in  connections   of 
secondary  batteries. 

44.  MISCELLANEOUS. 

a.  The  wiring  in  any  building  must 
test  free  from  grounds,  i.e.,  each  main 
supply  line  and  every  branch  circuit  shall 
have  an  insulation  resistance  of  at  least 
25,000  ohms,  and  should  have  an  insula- 
tion resistance  between  conductors  and 
between  all  conductors  and  the  ground 
87 


(not  including  attachments,  sockets,  etc.) 
of  not  less  than  the  following  : 


to   10  amp 

25 
50 

100     * 

200 
400 
800 
i.  600 

eres  4,000,000 
1,600,000 
800,000 

160,000 

80,000 

.       .     22  OOO 

1  1  .OOO 

All  cut-outs  and  safety  devices  in  place 
in  the  above. 

Where  lamp  sockets,  receptacles  and 
electroliers,  etc  ,  are  connected,  one  half 
of  the  above  will  be  required. 

b.  Ground   wires  for  lightning  arresters 
of  all  classes  and  ground  detectors  must 
not  be  attached    to  gas-pipes  within  the 
building. 

c.  Where  telephone,  telegraph,  or  other 
wires  connected  with  outside  circuits  are 
bunched  together  within   any  building,  or 
where  inside  wires  are  laid  in  conduit  or 
duct  with  electric  light  or   power   wires, 
the  covering  of  such  wires  must  be  fire- 
resisting,  or  else   the  wires    must  be  en- 
closed in  an  air-tight  tube  or  duct. 

d.  All  conductors  connecting  with  tele- 
phone,  district-messenger,   burglar-alarm, 
watch-clock,  electric-time,  and  other  simi- 
lar instruments,  must  be  provided  near  the 
point  of  entrance  to  the  building  with  some 


protective  device  which  will  operate  to 
shunt  the  instruments  in  case  of  a  danger- 
ous rise  of  potential,  and  will  open  the 
circuit  and  arrest  an  abnormal  current 
flow.  Any  conductor  normally  forming 
an  innocuous  circuit  may  become  a  source 
of  fire  hazard  if  crossed  with  another  con- 
ductor, through  which  it  may  become 
charged  with  a  relatively  high  pressure. 

e.  The  following  formula  for  soldering 
fluid  is  suggested : 

Saturated  solution  of  zinc 5  parts. 

Alcohol 4  parts. 

Glycerine i  part. 


APPENDIX/ 


Definition::  recommended  by  the  Electrical 
Committee  for  the  word  APPROVED 
as  used  in  the  Rules  of  Electric  Wiring 
recommended  by  the  Underwriters'  In- 
ternational Electric  Association. 

RULE  2.     CARE  AND  ATTENDANCE. 

Approved  waste  cans  shall  be  made  of 
metal,  with  legs  raising  can  three  inches 
from  the  floor,  and  with  self-closing  cov- 
ers. 

RULE  8.     MOTORS. 

Section  c>  From  the  nature  of  the  ques- 
tion, the  decision  as  to  what  is  an  approved 
case  must  be  left  to  the  Inspector  to  deter- 
mine in  each  instance. 
RULE  10.     OUTSIDE  CONDUCTORS. 

Section  a.  Insulation  that  will  be  ap- 
proved for  service  wires  must  be  solid,  at 
least  -^  of  an  inch  in  thickness,  and  cov- 
ered with  a  substantial  braid.  It  must  not 
readily  carry  fire,  must  show  an  insulating 
resistance  of  one  megohm  per  mile  after 
two  weeks'  submersion  in  water  at  70  de- 
grees Fahrenheit,  and  three  days'  subrner- 
91 


sion  in  lime  water,  with  a  current  of  550 
volts  and   after  three  minutes,  electrifica- 
tion. 
RULE  12.     INTERIOR  CONDUCTORS. 

Section  d.  Insulation  that  will  be  ap- 
proved for  interior  conductors  must  be 
solid,  at  least  -%\  of  an  inch  in  thickness, 
and  covered  with  a  substantial  braid.  It 
must  not  readily  carry  fire,  must  show  an 
insulating  resistance  of  one  megohm  per 
mile  after  two  weeks'  submersion  in  water 
at  70  degrees  Fahrenheit,  and  three  days' 
submersion  in  lime-water,  with  a  current 
of  550  volts  and  after  three  minutes'  elec- 
trification. 
RULE  13.  ARC  LAMPS. 

Section  c.  The  hand  switch  to  be  ap- 
proved, if  placed  anywhere  except  on  the 
lamp  itself,  must  comply  with  requirements 
for  switches  on  hanger-boards  as  laid  down 
in  new  Section  (g)  of  Rule  13. 
RULE  13.  ARC  LAMPS. 

Section  f.  An  approved  spark  arrester 
is  one  which  will  so  close  the  upper  orifice 
of  the  globe  that  it  will  be  impossible  for 
any  sparks  thrown  off  by  the  carbons  to 
escape. 

RULE  15.       OUTSIDE  OVERHEAD  CONDUCT- 
ORS. 

Section  b.  An  approved  fusible  cut-out 
92 


must  comply  with  the  sections  of  Rules 
23  and  24  describing  fuses  and  cut-outs. 
RULE  17. 

The  switch  required  by  this  rule  to  be 
approved  must  be  double  pole,  must  plainly 
indicate  whether  the  current  is  "  on  "  or 
"off,"  and  must  comply  with  Sections  a, 
c,  dt  and  e  of  Rule  26  relating  to  switches. 
RULE  18.  CONDUCTORS. 

Section  a.  In  so-called  "concealed"  wir- 
ing, moulding,  and  conduit  work,  and  in 
places  liable  to  be  exposed  to  dampness, 
the  insulating  covering  of  the  wire,  to  be 
approved,  must  be  solid,  at  least  -g±  of  an 
inch  in  thickness,  and  covered  with  a  sub- 
stantial braid.  It  must  not  readily  carry 
fire,  must  show  an  insulating  resistance  of 
one  megohm  per  mile  after  two  weeks' 
submersion  in  water  at  70  degrees  Fahren- 
heit, and  three  days'  submersion  in  lime- 
water,  with  a  current  of  550  volts  and  after 
three  minutes'  electrification. 

For  work  which  is  entirely  exposed  to 
view  throughout  the  whole  interior  cir-  " 
cults,  and  not  liable  to  be  exposed  to 
dampness,  a  wire  with  an  insulating  cov- 
ering that  will  not  support  combustion, 
will  resist  abrasion,  is  at  least -^  of  an  inch 
in  thickness,  and  thoroughly  impregnated 
with  a  moisture  repellent,  will  be  approved. 
93 


RULE  18.     CONDUCTORS. 

Section  b.  Second  paragraph.  Except 
for  FLOORS,  and  for  places  liable  to  be 
exposed  to  dampness,  Glass,  Porcelain^ 
metal-sheathed  Interior  Conduit,  and  Vulca 
Tube,  when  made  especially  for  bushings, 
will  be  approved. 

The  two  last  named  will  not  be  approved 
If  cut  from  the  usual  lengths  of  tube  made 
for  conduit  work,  nor  when  made  without  a 
head  or  flange  on  one  end. 

RULE  21.     SPECIAL  WIRING. 

Section  b.  The  insulating  covering  of 
the  wire  to  be  approved  under  this  section 
must  be  solid,  at  least  -^  of  an  inch  in 
thickness,  and  covered  with  a  substantial 
braid.  It  must  not  readily  carry  fire,  must 
show  an  insulating  resistance  of  one  meg- 
ohm per  mile  after  two  weeks'  submersion 
in  water  at  70  degrees  Fahrenheit,  and 
three  days'  submersion  in  lime-water  with 
a  current  of  550  volts  after  three  minutes' 
electrification,  and  must  also  withstand  a 
satisfactory  test  against  such  chemical 
compounds  or  mixtures  as  it  will  be  liable 
to  be  subjected  to  in  the  risk  under  con- 
sideration. 
RULE  23.  DOUBLE  POLE  SAFETY  CUT-OUTS. 

Section  a.  To  be  approved,  boxes  must 

be    constructed,   and    cut-outs    arranged, 

whether  in  a  box  or  not,  so  as  to  obviate 

any  danger  of  the  melted  fuse  metal  com- 

94 


ing  in  contact  with  any  substance  which 
might  be  ignited  thereby. 

RULE  27.     FIXTURE  WORK. 

Section  a.  Insulating  joints  to  be  ap- 
proved must  be  entirely  made  of  material 
that  will  resist  the  action  of  illuminating 
gases,  and  will  not  give  way  or  soften 
under  the  heat  of  an  ordinary  gas  flame. 
They  shall  be  so  arranged  that  a  deposit 
of  moisture  will  not  destroy  the  insulating 
effect,  and  shall  have  an  insulating  resist- 
ance of  250,000  ohms  between  the  gas-pipe 
attachments,  and  be  sufficiently  strong  to 
resist  the  strain  they  will  be  liable  to  in 
attachment. 

RULE  37.     POWER  STATIONS. 

Section  a.  Automatic  circuit-breakers 
should  be  submitted  to  the  Committee  for 
approval  before  being  used. 

RULE  43.      STORAGE    OR    PRIMARY    BAT- 
TERIES. 

Section  b.  Insulators  for  mounting  sec- 
ondary batteries  to  be  approved  must  be 
non-combustible,  such  as  glass,  or  thor- 
oughly vitrified  and  glazed  porcelain. 


95 


Recommendations  of  the  Electrical  Com- 
mittee as  to  approval  of  certain  wires 
and  materials,  and  the  interpretation 
of  certain  rules. 

RULE  4.     SWITCH-BOARDS. 

Section  a.  Special  attention  is  called  to 
the  fact  that  switch-boards  should  not  be 
built  down  to  the  floor,  nor  up  to  the  ceil- 
ing, but  a  space  of  at  least  eighteen  inches 
or  two  feet,  should  be  left  between  the 
floor  and  the  board,  and  between  the  ceil- 
ing and  the  board,  in  order  to  prevent 
fire  from  communicating  from  the  switch- 
board to  the  floor  or  ceiling,  and  also  to 
p'revent  the  forming  of  a  partially  con- 
cealed space  very  liable  to  be  used  for 
storage  of  rubbish  and  oily  waste. 
RULE  5  RESISTANCE  BOXES. 

Section  a.  The    word    "  frame"  in  this 
section  relates  to  the  entire  case  and  sur- 
rounding of  the  rheostat,  and  not  alone  to 
the  upholding  supports. 
RULE  9.     RESISTANCE  BOXES. 

Section  a.   The   word    "  frame"    in  this 
section  relates  to  the  entire  case  and  sur- 
rounding of  the  rheostat,  and  not  alone  to 
the  upholding  supports. 
CLASS  B. 

It  is  the  sense  of  the   Electrical  Com- 
mittee that   any  circuit   attached  to  any 
96 


machine  or  combination  of  machines, 
which  develop  over  300  volts  difference  of 
potential  between  any  two  wires,  shall  be 
considered  as  a  high  potential  circuit  and 
coming  under  that  class,  unless  an  ap- 
proved transforming  device  is  used,  which 
cuts  the  difference  of  potential  down  to 
less  than  300  volts. 
RULE  10.  OUTSIDE  CONDUCTORS. 

Section/.  It  is  the  sense  of  the  Electri- 
cal Committee  that  all  joints  must  be 
soldered,  even  if  made  with  the  Mclntyre 
or  any  other  patent  splicing  device.  This 
ruling  applies  to  joints  and  splices  in  all 
classes  of  wiring  covered  by  these  Rules. 
RULE  15.  OUTSIDE  OVERHEAD  CONDUCT- 
ORS. 

Section  b.  The  cut-out  required  by.this 
section  must  be  placed   so  as  to  protect 
the  switch  required  by  Rule  17. 
RULE  16.     UNDERGROUND  CONDUCTORS. 

Section  b.   The  cut-out  required  by  this 
section   must  be  placed  so  as  to  protect 
the  switch. 
RULE  22.     INTERIOR  CONDUITS. 

It  is  recommended  that  the  American 
Circular  Loom  Co.  Tube,  the  metal- 
sheathed  Interior  Conduit  Tube,  and  the 
Vulca  Tube  be  approved  for  the  class  of 
work  called  for  in  this  rule. 
97 


MATERIALS. 

The  following  are  given  as  a  list  of  non- 
combustible,  non  -  absorptive,  insulating 
materials,  and  are  listed  here  for  the  bene- 
fit of  those  who  might  consider  hard  rub- 
ber, fiber,  wood,  and  the  like,  as  fulfilling 
the  above  requirements.  Any  other  sub- 
stance which  it  is  claimed  should  be  ac- 
cepted, must  be  forwarded  for  testing  be- 
fore being  put  on  the  market. 

1.  Thoroughly  vitrified  and  glazed  Por- 
celain. 

2.  Glass. 

3.  Slate  without  metal  veins, 

4.  Pure  Sheet  Mica. 

5.  Marble  (filled). 

6.  Lava  (certain  kinds  of). 

WIRES. 

The  following  is  a  list  of  wires  which 
have  been  tested  by  the  Committee  and 
found  to  comply  with  the  requirements 
for  an  approved  insulation  under  Rule  10 
(a),  Rule  12  (d),  and  Rule  18  (a). 

Americanite. 

Bishop. 

Canvasite. 

Clark. 

Edison  Machine. 

Grimshaw  (white  core), 

Habirshaw  (red  core). 
98 


Kerite. 

National  India  Rubber  Co.  (N.  I.  R.). 

Okonite. 

Paranite. 

Raven  Core. 

c   ,  .     r       i  «.    i    ^  Requa  white  core.  ) 
Safety  Insulated 

(  Safety  black  core.  > 

Salamander  (rubber  covered). 

Simplex  (caoutchouc). 

None  of  the  above  wires  to  be  used 
unless  protected  with  a  substantial  braided 
outer  covering. 


Rules  Recommended  by  the  Electrical 
Committee  for  the  Introduction  of 
Automatic  Fire-alarm  Systems. 

THERMOSTATS  must  be  placed— 

1.  Not  more  than  15  feet  apart. 

2.  Not  more  than  10  feet  from  any  side 
of  any-room. 

3.  Not  more  than   5  feet  from  any  side 
of  any  room   having  window's   or   similar 
openings. 

4.  In  every  room  in  the  building  which 
is  separated   by   partitions   running   from 
the  floor  to  the  ceiling. 

5.  At  the  top  of  each  elevator  well  and 
hoistway  in  the  building. 

6.  In  any  particular  places  required  by 
the  Inspector  of  the  Association. 

7.  In  buildings  of  so-called  bay  construc- 
tion, so  that  there  shall  be  a  line  in  each 
bay,  unless  the  thermostats  are  placed  on 
a  level  with  the  lower  side  of  the  timbers 
forming  the  bays. 

WIRES  INSIDE  BUILDINGS— 

1.  Must  be   equivalent  in   conductivity 
and   tensile   strength  to  No.    18   B.   &  S. 
copper  wire, 

2.  Must   have    an   approved    insulating 
covering. 

3.  Unless   encased   in    metal  pipes,  ap- 

100 


proved  tubing,  or  thoroughly  filled  mould- 
ing, must  be  run  in  plain  sight  and  sup- 
ported entirely  on  non-combustible  insula- 
tors. 

4.  Must  be  protected  from  abrasion  and 
from  accidental  contact  with  other  con- 
ductors. 

WIRES  OUTSIDE  BUILDINGS— 

1.  Must  be  equivalent   in   conductivity 
and  tensile  strength  to  No.  12  galvanized 
iron  wire. 

2.  Must   have   an   approved    insulating 
covering. 

3.  Must  have  their  routes  recorded  by 
plans  filed  at  the  Central  station  of  the 
alarm  company  operating  them. 

4.  Must  be  provided  near  the  point  of 
entrance  to  the  building  with  some  protec- 
tive device,  which  will  operate  to  shunt  the 
inside  wires  and  apparatus   in    case  of  a 
dangerous  rise  of  potential,  and  will  open 
the  circuit  and  arrest  an  abnormal  current 
flow. 

MANUAL  ALARMS— 

Must  be  located  near  all  main  and  floor 
exits. 

ALARM  GONGS— 

Must  be  installed  in  all  buildings  having 
a  watchman. 

101 


IN     SYSTEMS     OPERATING     WITHOUT     A 
CENTRAL  STATION  there  shall  be— 

1.  An   annuuciator    on    the    outside   of 
each  risk. 

2.  A  gong  not  less  than  seven  inches  in 
diameter  on  the  outside  of  each  risk. 

3.  Some  means  by  which  the  entire  sys- 
tem can  be  tested   daily,   and   also  some 
method  by  which  any  trouble  which  may 
arise  will  be  located  by  this  test. 

4.  At    least    two    outside   connections, 
besides  the  gong  on   the  outside  of  the 
building    itself.     As  a  general    rule  these 
should    be   selected    from    the    following 
list,  taking  the  first  two  that  are   possible 
in  any  particular  risk  : 

(/?)  The  nearest  fire  department  house 
where  there  are  permanent  men 
stationed. 

(b)  The  house  of  the  owner,  or  some 
responsible    employee   of    the    risk 
equipped,  which  must  be  within  rea- 
sonable distance  of  the  risk. 

(c)  The  house  of  some  other  party  as 
described  in  Section  (b). 

(d)  In  some  of  the  larger  cities  with 
paid  city  fire-departments  the  first 
connection  alone  may  be  accepted. 

5.  A    metallic    circuit    for    the    whole 
system. 

102 


NOTE.— It  will  be  seen  that  the  above 
rules  do  not  in  any  way  relate  to  what 
systems  shall  be  approved.  The  Com- 
mittee have  not  yet  found  it  possible  to 
enter  into  this  subject,  or  to  formulate 
detailed  rules  as  to  what  a  system  shall 
accomplish  or  how  it  shall  do  it,  or  what 
the  construction  of  the  thermostats  and 
other  apparatus  should  be. 

These  rules  simply  relate  to  how  a  sys- 
tem which  has  been  approved  by  any  Board 
or  Association  should  be  installed  so  as  to 
secure  the  best  and  most  permanent  effi- 
ciency from  such  system,  regardless  of  the 
merits  or  demerits  of  the  svstem  itself. 


103 


ALTERNATING   CURRENT   WIRING. 

THE  following  tables,  calculated  from 
Kennelly's  formula,  give  the  increase  of 
drop  due  to  impedance  in  circuits  carry- 
ing alternating  currents. 

Each  table  is  for  a  different  frequency, 
as  given  :  the  first  vertical  column  of  a 
table  gives  the  gauge  of  wire,  the  hori- 
zontal column  at  the  top  the  distance 
apart  of  the  two  wires  of  a  circuit, 
and  the  other  columns  the  coefficients 
by  which  the  drop  due  to  a  continuous 
current  should  be  multiplied  to  find  the 
true  drop  if  an  alternating  current  is 
used. 

To  lower  the  drop  due  to  impedance 
it  will  be  seen  that  large  wires  should  be 
avoided.  In  inside  work,  particularly,  a 
considerable  saving  of  copper  may  often 
be  made  by  dividing  the  feeders  or  mains 
into  several  circuits. 

The  following  method  will  enable  the 
tables  to  be  applied  with  an  approximation 
sufficiently  close  for  practical  purposes : 

i°  By  means  of  one  of  the  formulas  on 
pages  n,  12,  and  13  calculate,  for  the 
given  lamps,  amperes,  or  horse-power, 
the  size  of  the  wire  (in  circular  mils)  as 
if  a  continuous  current  were  to  be  used, 
104 


and  from  Table  IX.  find  the  nearest 
corresponding  B.  &  S.  gauge  number. 

2°  Enter  with  the  gauge  thus  found  that 
one  of  the  following  tables  which  cor- 
responds with  the  periodicity  used 
and  take  out  the  corresponding  co- 
efficient. 

3°  Multiply  the  original  circular  mils  by 
this  coefficient  and  find  the  correspond- 
ing gauge  again  from  Table  IX. 

4°  Repeat  the  operation  of  2°. 

5  Multiply  the  original  circular  mils  by 
this  second  coefficient  and  proceed 
otherwise  as  in  3°. 

EXAMPLE.  Amperes,  20;  volts,  1000; 
drop,  5  per  cent ;  distance,  4000  feet ;  peri- 
odicity, 130;  distance  of  wires  apart,  18 
inches. 

i°   From  formula  (2),  page  11, 

2i$oLC       2150  x  4000  x  20 

A  =  —«E~      -rin^  =344°° 

or  about  No.  5  B.  cS:  S.  gauge. 

2"  Referring  to  Table  XXIII.,  we  get  the 
coefficient  1.38. 

3°  34400  x  1.38  =  47472  cir.  mils,  or  be- 
tween gauges  3  and  4. 

4°  Referring  to  Table  XXIII.,  we  find  the 
corresponding  coefficient  to  be  about 
1.44. 

105 


5°  344oo  x  144  =  49536,  or  about  gauge 
No.  3. 

If  thought  necessary  a  third  or  fourth 
approximation  may  be  made  by  repeating 
the  operations  indicated  in  4°  and  5°. 


The  above  rules  and  the  tables  apply  to 
alternating  currents  that  can  be  repre- 
sented by  simple  sine  waves  (sinusoids). 
If  the  current  waves  are  of  more  complex 
type,  the  drop  due  to  impedance  will  be 
increased.  The  above  values  are  there- 
fore minimum  values. 

The  tables  are  based  on  the  assumption 
that  the  current  density  in  a  conductor 
remains  uniform.  With  the  frequencies 
used  the  error  thus  introduced  is  entirely 
negligible  as  relates  to  the  calculation  of 
impedances,  as  well  as  to  the  increase  of 
drop  due  to  the  unequal  distribution  of 
current  in  a  conductor. 


106 


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DIAGRAMS. 

e       I.    Two-wire  incandescent  system. 

II.    Three-wire 
III. 

IV.    Alternating  system. 
V.    Incandescent  system,  usual. 
VI.    Arc   and    incandescent    series 

system,  little  used. 
VII.    Arc   and    incandescent   series 
and  incandescent  multiple, 
little  used. 
VIII.    Arc  system. 

IX.    Series-wound  dynamo  (arc). 
X.    Shunt-wound  dynamo  (incan- 
descent or  arc). 

XL    Compound-wound  dynamo. 
XII.    Alternating  system. 

XIII.  Closed  and  open  circuit  arma- 

tures. 

XIV.  Siemens,  Gramme,  and  alter 

nator  windings. 


I. 


X 


X 


X 


X 
X 

a/ 


III. 


00- 


IV, 


V. 


MULTIPLE 


SERIES 


VII. 


IX. 


X. 


T 


XI. 


\   \  V  \ 


xn 


[     CONVERTERS 


VY  VY 

upp    uX/ 


XIII. 


INDEX. 

PAGE 

Alternating  current  wiring  rules  and  tables  .   ........  107 

Boilers,  horse-power  of  ......................  .......  47 

Circuits,  incandescent,  rules  for  ......................  5 

Closet  system  of  wiring  ...............................  9 

Copper  wire,  bare,  dimensions,  etc  ..............  ......  30 

11     insulated,  weight  of  ,  etc  ...............  33 

Cross-arms,  dimensions  of  ...........................  40 

Electrical  units  ............  .........................  42 

Engines,  horse-power  of  ..............................  46 

Equivalents  of  wires  (for  cabling,  etc.)  ...........   .  .  36 


Formulae  for  wiring 
Fusing  points  of  variou 


sing  points  of  various  wires 


Gas  jets,  air  vitiated  by  ...........................  .  .  41 

Gauges,  comparison  of  ...............................  32 

Edison  -----  ..................................  31 

Gears,  rules  for  calculating  .........................  50 

German-silver  wire,  resistance  of  ....................  39 

Globes,  light  cut  off  by  ..............................  41 

Heating  limits,  interior  wires  ...............   .......  34 

exterior  lines  .......................  35 

Horse-power  of  boilers  ...............................  47 

"  engines  ...............  .  .............  46 

Incandescent  circuits,  rules  for  ...................      5 

Instructions  for  wiremen  and  linemen  ...............  51 

Iron  wire,  resistance  and  weight  of  ..................  39 

Lamp  centres  defined  ................................    8 

Lamps,  arc,  candle-power  of  ..........  .  .............  41 

1     heat  from  ...........................  41 

"       incandescent,  heat  from  .....................  41 

Material  for  installing  arc  lamps  ...................  45 

Poles,  wreight  and  dimensions  of  .........  .  ...........  40 

Pulleys,  rules  for  calculating  ...................  ____  49 

Resistance  of  copper  wire  ............................  30 

"  different  materials  ...................  38 

"          "  German  silver  wire  ....................  39 

"         "  iron  wire  ...................  ........  39 

Underwriters'  rules  ................................  59 

Supplies  for  installing  arc  lamps.   .................  45 

Tools  for  installing  city  plant  .......................  44 

Tree  system  of  wiring  ................................    9 

Units,  electrical  .....................................  42 

Voltmeters,  connecting  up  ...........................  10 

Wiring  formulae  .....  ..............................  11 

table,  50  volts  ..............  .........  ........  14 

"      75     "     .................................  16 

4    110     "      ................................  18 

*  220     "     .............................  20 

'    500     "     ...............  .................  22 

'  1000     **     ................................  24 

*  2000     "     ................................  26 

'  three-  wire  system  .  .  .....................  20 

'  odd  voltages  .........     .  .  .................  28 

"   percentages  .........  .  ..............  29 

128 


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ELECTRICITY  AND  MAGNETISM: 

A  Series  of  Advanced  Primers. 

By  Prof,  EDWIN  J.  HOUSTON, 

AUTHOR   OF 

A  Dictionary  of  Electrical  Words,  Terms  and  Phrases, 


Cloth.   306Pages,  116  Illustrations.   Price,  §1.00. 


Prof.  Houston's  Primers  of  Electricity  written  in 
1884  enjoyed  a  wide  circulation,  not  only  in  the 
United  States  but  in  Europe,  and  for  some  time 
have  been  out  of  print.  Owing  to  the  great  prog- 
ress in  electricity  since  that  date  the  author  has» 
been  led  to  prepare  an  entirely  new  series  of 
primers,  but  of  a  mpre  advanced  character  in  con- 
sonance with  the  advanced  general  knowledge  of 
electricity. 

Electricians  will  find  these  primers  of  marked 
interest  from  their  lucid  explanations  of  principles, 
and  the  general  public  will  in  them  find  an  easily 
read  and  agreeable  introduction  to  a  fascinating 
subject. 

CONTENTS. 

I.— Effects  of  Electric  Charge.  II.— Insulators  and  Con- 
ductors. III. — Effects  of  an  Electric  Discharge.  IV. — 
Electric  Sources.  V.— Electro-receptive  Devices.  VI.— 
Electric  Current.  VII.— Electric  Units.  VIII.— Electric 
Work  and  Power.  IX. — Varieties  of  Electric  Circuits. 
X.— Magnetism.  XI.  — Magnetic  Induction.  XII.— The- 
ories of  Magnetism.  XIII.— Phenomena  of  the  Earth's 
Magnetism.  XIV. — Electro-Magnets.  XV. — Electrostatic 
Induction.  XVI. — Frictional  and  Influence  Machines. 
XVII.— Atmospheric  Electricity.  XVIII.— Voltaic  Cells. 
XIX.  — Review,  Primer  of  Primers. 

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JUST    PUBLISHED. 

THE    ELECTRIC    RAILWAY 

In  Theory   and    Practice. 

By  O.  T.  CROSBY  and  Dr.  LOUIS   BELL. 

400  Octavo   Pages.      179  Illustrations.      Price,   $2.*>0, 

This  is  the  first  Systematic  Treatise  that  has  been  pub- 
lished on  the  Electric  Railway,  and  it  is  intended 
to  cover  the  General    Principles  of  Design, 
Construction  and  Operation. 

TABLE   OF  CONTENTS. 

Chapter     I.  General  Electrical  Theory. 

II.  Prime  Movers. 

III.  Motors  and  Car  Equipment. 

IV.  The  Line. 

V.  Track,  Car  Mouses,  Snow  Machines. 

VI.  The  Station. 

VII.  The  Efficiency  of  Electric  Traction. 

VIII.  Storage  Battery  Traction. 

IX.  Miscellaneous    Methods   of    Electric 

Traction. 

X.  High  Speed  Service. 

XI.  Commercial  Considerations. 

XII.  Historical  Notes. 

APPENDICES. 

Appendix  A.      Electric  Railway  vs.  Telephone  De- 
cisions. 

B.      Instructions  to  Linemen. 
"         C.     Engineer's  Log  Book. 
"         D.     Classification    of    Expenditures    of 

Electric  Street  Railways. 

"         E.      Concerning   Lightning  Protection, 
by  Prof.  Elihu  Thomson. 

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THE  ELECTRIC  MOTOR 

AND   ITS  APPLICATIONS. 

By    T.     C.     MARTIN     and     JOSEPH    W.ETZLER. 

WITH  AN  APPENDIX   BRINGING  THE  BOOK  DOWN 

TO  DATE,  BY 
DR.     LOUIS     BELL. 


325  Large  Quarto  Pages  and  354  Illustrations.    Price, 
postage  prepaid  to  any  part  of  the  world,  $3.00. 


This  timely  work  is  the  first  American  Book  on 
Electric  Motors,  and  the  only  book  in  any  lan- 
guage dealing  exclusively  and  fully  with  the 
modern  Electric  Motor  in  all  its  various  practical 
applications.  The  book  is  a  handsome  quarto,  the 
page  being  of  the  same  size  as  Dredge's  large 
work  on  "  Electric  Illumination."  and  many  of  the 
cuts  are  full  page. 

No  effort  has  been  spared  to  make  the  book 
complete  to  date,  and  it  will  prove  invaluable  to 
every  one  interested  in  the  progress  and  develop- 
ment of  the  Electric  Motor  or  the  Electrical  Trans- 
mission of  Energy. 

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AN    IMPORTANT    NEW    BOOK. 


ALTERNATING  CURRENTS. 

An  Analytical  and  Graphical  Treatment 
for  Students  and  Engineers. 


FREDERICK  BEDELL,  Ph.D,,  and  A,  C,  CREHORE,  Ph.D,  Cor,  Univ, 

Uniform  in  size  and  style  with  "  The  Electric  Railway 

in  Theory  and  Practice,11  by  O.  T.  Crosby 

and  Dr.  Louis  Bell. 


Cloth.     350  Pages  and  11 '2  Illustrations.    Price,  $2.50, 


While  there  are  many  monographs  and  special 
treatises  on  alternating  currents,  they  are  either 
fragmentary  or  special  in  character,  or  couched  in 
mathematical  language  requiring  a  special  mathe- 
matical education  to  interpret. 

In  this  volume  the  theory  of  alternating  currents 
is,  for  the  first  time,  treated  in  a  connected  and 
logical  manner,  and  in  mathematical  language 
familiar  to  the  ordinary  mathematical  public, 
while  the  graphical  extension  can  be  followed  by 
those  not  having  a  special  knowledge  of  mathe- 
matics. 

Some  parts  of  this  volume  have  been  published 
in  separate  papers,  and  from  the  cordial  welcome 
they  received,  it  is  believed  that  the  present  work 
will  fill  a  distinct  want  in  an  important  branch  of 
electrical  science. 

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PRINCIPLES   OF 

DYNAMO-ELECTRIC  MACHINES 

AND 

Practical  Directions  for  Designing 
and  Constructing  Dynamos. 

By   CARL.   HERING. 


Sixth  Thousand.  279pp.  59  Illustrations.  Price,  $2.50 


CONTENTS. 

Review  of  Electrical  Units  and  Fundamental  Laws. 

Fundamental  Principles  of  Dynamos  and  Motors. 

Magnetism  and  Electromagnetic  Induction. 

Generation  of  Electromotive  Force  in  Dynamos. 

Armatures. 

Calculation  of  Armatures. 

Field  Magnet  Frames. 

Field  Magnet  Coils. 

Regulation  of  Machines. 

Examining  Machines. 

Practical  Deductions  from  the  Franklin  Institute 
Tests  of  Dynamos. 

The  So-called  "  Dead  Wire"  on  Gramme  Arma- 
tures. 

Explorations  of  Magnetic  Fields  Surrounding 
Dynamos. 

Systems  of  Cylinder- Armature  Windings. 

Table  of  Equivalents  of  Units  of  Measurements. 

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ELECTRIC    LIGHTING 

SPECIFICATIONS 

FOR   THE    USE    OF 

Engineers  and  Architects. 

By  E.  A.    MERRILL. 


€loth.      170  Pages.     Price,    including  Postage,  $1.50. 


The  author  has  drawn  up  a  set  of  specifications 
covering  the  various  classes  of  lighting  installa- 
tions, which  will  serve  as  forms  for  any  special 
type  or  character  of  plant,  ind  which  are  at  the 
same  time  full  enough  to  cover  the  ordinary  instal- 
lation of  electrical  apparatus  and  '.\ectric  light  wir- 
ing. The  book  will  prove  especially  useful  to 
architects  and  engineers  who  desire  a  full  knowl- 
edge of  the  necessary  requirements  of  the  various 
classes  of  electrical  installations  in  order  to  meet 
the  demands  of  the  insurance  inspectors  and  the 
conditions  of  safety.  The  latest  rules  are  given  of 
the  (i)  National  Electric  Light  Association, 
(2)  National  Board  of  Fire  Underwriters,  (3)  New 
England  Insurance*  Exchange. 

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EXPERIflENTS   WITH 

ALTERNATE  CURRENTS 

Of  High  Potential  and  High  Frequency. 
By   NIKOLA   TESLA. 


156  Pages,  with   Portrait  and  35  Illus.    Cloth.    $1.00. 


This  book  gives  in  full  Mr.  Tesla's  important 
lecture  before  the  London  Institution  of  Electrical 
Engineers,  which  embodies  the  results  of  years  of 
patient  study  and  investigation  on  Mr.  Tesla's  par- 
of  the  phenomena  of  Alternating  Currents  of  Enort 
mously  High  Frequency  and  Electromotive  Force. 

EVERY  ELECTRICIAN,  ELECTRICAL 
ENGINEER  OR  STUDENT  OF  ELECTRIC- 
AL PHENOMENA  WHO  MAKES  ANY  PRE- 
TENSIONS TO  THOROUGH  ACQUAINT- 
ANCE WITH  RECENT  PROGRESS  IN  THIS 
IMPORTANT  FIELD  OF  RESEARCH 
WHICH  MR.  TESLA  HAS  SO  ABLY  DE 
VELOPED  MUST  READ  AND  REREAD 
THIS  LECTURE. 

The  book  is  well  illustrated  with  35  cuts  of  Mr. 
Tesla's  experimental  apparatus,  and  contains  in 
addition  a  biographical  sketch,  accompanied  by  a 
full-page  portrait,  which  forms  a  fitting  frontispiece 
to  a  lecture  which  created  such  widespread  interest. 

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RECENT    PROGRESS 

IN 

ELECTRIC     RAILWAYS 

BEING  A  SUMMARY  OF  CURRENT  PROGRESS 

IN  ELECTRIC  RAILWAY  CONSTRUCTION, 

OPERATION,  SYSTEMS,  MACHINERY, 

APPLIANCES,   ETC. 

COMPILED    11 V 


380  Pages  and  120  Illustrations.    Cloth.    Price,  $1.00. 


This  volume  contains  a  classified  summary  of 
the  recent  literature  on  this  active  and  promising 
branch  of  electrical  progress,  with  descriptions  of 
new  apparatus  and  devices  of  general  interest. 


CONTENTS. 

Chapter  I. — Historical.  Chapter  II. — Develop- 
ment and  Statistics.  Chapter  III. — Construction 
and  Operation.  Chapter  IV. — Cost  of  Construc- 
tion and  Operation.  Chapter  V. — Overhead  Wire 
Surface  Roads.  Chapter  VI. — Conduit  and  Surface 
Conductor  Roads.  Chapter  VII.— Storage  Battery 
Roads.  Chapter  VIII.  —  Underground  Tunnel 
Roads.  Chapter  IX.  —  High  Speed  Interurban 
Railroads  Chapter  X. — Miscellaneous  Systems. 
Chapter  XI. — Generators,  Motors  and  Trucks. 
Chapter  XII. — Accessories. 

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ORIGINAL  PAPERS 


DYNAMO  MACHINERY 

AND   ALLIED  SUBJECTS. 
By  JOHN  HOPKINSON,  F.E.S. 

Uniform  in  size,   style  and    price  with    Thompson's 
Lectures  on  the  Electromagnet. 


Cloth.      257  Pages.      98  Illustrations.     Price,  $1.00. 


This  collection  of  papers  includes  all  written  on 
electro-technical  subjects  by  the  distinguished 
author,  most  of  which  have  been  epochal  in  their 
character  and  results. 

The  papers  are  arranged  according  to  subject. 
Five  papers  relate  wholly  or  in  part  to  the  contin- 
uous current  dynamo  ;  four  are  on  converters  and 
one  each  on  the  theory  of  alternating  current 
machines  and  on  the  application  of  electricity  to 
light-houses. 

In  the  words  of  the  author,  "  The  motive  of  this 
publication  has  been  that  I  have  understood  that 
one  or  two  of  these  papers  are  out  of  print  and  not 
so  accessible  to  American  readers  as  an  author  who 
very  greatly  values  the  good  opinion  of  American 
electrical  engineers  would  desire." 

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THE  ELECTROHAGNET. 

r-Y 

Prof,  SILVANUS  P,  THOMPSON,  D,Sc,f  B,AM  M.I.E.E, 

A  full  theoretical  and  practical  account  of  the  proper- 
ties and  peculiarities  of  electromagnets,  together 
with   complete   instructions  for    designing 

magnets  to  serve  any  specific  purpose. 

Published  with  the   express  consent  and   careful 

revision  of  the  author. 

Cloth.     280   Pages.      75    Illustrations.     Price,  $1.00. 


LECTURE  I.:  Introductory  ;  Historical  Sketch  ;  Gener- 
alities Concerning  Electromagnets ;  Typical  Forms ;  Po- 
Jarity  ;  Uses  in  General  ;  The  Properties  of  Iron  ;  Methods 
of  Measuring  Permeability  ;  Traction  Methods  ;  Curves  of 
Magnetization  and  Permeability  ;  The  Law  of  the  Electro- 
magnet;  Hysteresis;  Fallacies  and  Facts  about  Electro- 
magnets. LECTURE  II,:  General  Principles  of  Design  and 
Construction  ;  Principle  of  the  Magnetic  Circuit.  LECTURE 
III.:  Special  Designs  ;  Winding  of  the  Copper  ;  Windings 
for  Constant  Pressure  and  for  Constant  Current  ;  Miscel- 
laneous Rules  about  Winding  ;  Specifications  for  Electro- 
magnets ;  Amateur  Rules  about  Resistance  of  Electromag- 
net and  Battery  ;  Forms  of  Electromagnets  ;  Effect  of  Size 
of  Coils  ;  Effect  of  Position  of  Coils  ;  Effect  of  Shape  of 
Section  ;  Effect  of  Distance  between  Poles  ;  Researches 
of  Prof.  Hughes;  Position  and  Form  of  Armature,  Pole- 
Pieces  on  Horseshoe  Magnets  ;  Contrast  between  Electro- 
magnets and  Permanent  Magnets  ;  Electromagnets  for 
Maximum  Traction  ;  Electromagnets  for  Maximum  Range 
of  Attraction  ;  Electromagnets  of  Minimum  Weight  ;  A 
Useful  Guiding  Principle  ;  Electromagnets  for  Use  with 
Alternating  Currents ;  Electromagnets  for  Quickest  Ac- 
tion ;  Connecting  Coils  for  Quickest  Action;  Battery- 
Grouping  ff  r  Quickest  Action ;  Short  Cores  vs.  Long 
Cores.  LECTURE  IV.:  Electromagnetism,  etc. 

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THEQUADRUPLEX. 

BY 

WM,  MAVER,  Jr.,  and  MINOR  M,  DAVIS, 

With  Chapters  on  The  Dynamo-Electric  Machine  in 
Relation  to  the  Quadruplex.     The  Practical  Work- 
ing of  the  Quadruplex.      Telegraph  Repeaters 
and  the  Wheatstone  Automatic  Telegraph. 
By  WM.  MAVER,  Jr. 


Cloth.     126   Pages.      63    Illustrations.     Price,  $l.oO. 

CONTENTS. 

Development  of  the  Quadruplex. 

Introduction  and  Explanatory. 

The  Transmitter,  Rheostat  and  the  Condenser. 

Stearns  Duplex. 

Instruments  of  the  Polar  Duplex. 

The  Polar  Duplex. 

The  Quadruplex. 

The  Dynamo-Electric  Machine  in   relation  to  ihe 

Quad. 

The  Practical  Working  of  the  Quadruplex. 
Telegraph  Repeaters. 
The  Wheatstone  Automatic  Telegraph. 


This  book  is  written  in  plain,  simple  and  explicit 
language,  and  is  within  the  ready  comprehension 
of  all.  The  illustrations  are  numerous,  and  with 
their  aid  the  reader  can  at  once  grasp,  menta/iy, 
the  operation  of  the  Quadruplex.  The  book  is 
handsomely  printed  on  fine  paper  and  substantially 
bound.  Every  Telegrapher  and  every  Electrician 
should  have  a  copy. 

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ELEMENTS    OF 

STATIC  ELECTRICITY, 

With  full  description  of  the  Holtz  and  To'pler 
flachines  and  their  mode  of  operation. 

By  PHILIP  ATKINSON,  A.M.,  Ph.D. 


Cloth,  12mo.  2-28  Pages.  «4  Illustrations.    Price,  $1.50. 

The  author  of  this  treatise  has  made  a  special 
study  of  Static  Electricity,  and  is  an  acknowledged 
master  of  the  subject.  The  book  embodies  the 
result  of  much  original  investigation  and  experi- 
ment, which  Dr.  Atkinson's  long  experience  as  a 
teacher  enables  him  to  describe  in  clear  and  inter- 
esting language,  devoid  of  technicalities. 

The  principles  of  electricity  are  presented  un- 
trammeled,  as  far  as  possible,  by  mathematical 
formulae,  so  as  to  meet  the  requirements  of  a  large 
class  who  have  not  the  time  or  opportunity  to  mas- 
ter the  intricacies  of  formulae,  which  are  usually  so 
perplexing  to  all  but  expert  mathematicians. 

The  views  expressed  in  the  book  are  the  result  of 
many  years'  experience  in  the  class  room,  the  lee 
ture  room  and  the  laboratory,  and  were  adopted 
only  after  the  most  rigid  test  of  actual  and  oft- 
repeated  experiment  by  the  author. 

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TH 


UNIVERSAL  WIRING  COMPUTER. 

By  CARL  HEBING, 

Author  of  "  Principles  of  Dynamo-Electric  Machines," 
"  Magnet  Winding,'1  etc. 


Convenient  Size  for  the  Pocket.     Cloth.     Price,  $1.00. 


Gives  the  sizes  of  wires  directly  in  circular  mils 
or  in  gauge  numbers,  for  any  make  of  lamp  (or  any 
horse  power  of  current),  for  any  loss,  for  any 
number  of  lamps,  and  at  any  distances,  without  cal- 
culations, for mu Ice  or  knowledge  of  mathematics. 

It  is  the  equivalent  of  a  complete  set  of  tables 
for  all  practical  cases,  with  the  advantage  over 
these  of  being  much  simpler,  more  compact  and 
handy  than  such  a  cumbersome  and  bulky  set  of 
tables  would  be.  It  gives  the  result  in  as  little 
time  as  it  would  otherwise  take  to  write  down  the 
figures  to  perform  the  calculation. 

The  book  includes  also  an  illustrated  article  giv- 
ing general  hints  on  wiring  and  a  set  of  original 
Useful  Auxiliary  Tables,  such  as  for  heating  limits, 
weights  of  insulation,  power  reductions,  composite 
wires  of  large  sections,  weights  and  resistances, 
wire  gauges,  etc. 

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Practical  Information  for  Telephonists, 

By  T.   D.   LOCKWOOD, 

ELECTRICIAN  AMERICAN   BELL   TELEPHONE   COMPANY. 

12nio.     192   Pages.     Cloth.    Price,   $1.00. 

CONTENTS. 

Historical  Sketch  of  Electricity  from  600  B.C.   to 

1882  A.D. 

Facts  and  Figures  about  the  Speaking  Telephone. 
How   to    Build   a   Short   Telegraph  or  Telephone 

Line. 
The  Earth  and  Its  Relation  to  Telephonic  Systems 

of  Communication. 
The   Magneto-Telephone — What   it   is,  How   it  is 

Made,  and  How  it  Should  be  Handled. 
The  Blake  Transmitter. 

Disturbances  Experienced  on  Telephone  Lines. 
The  Telephone    Switch- Board. 
A  Chronological    Sketch  of  the  Magneto-Bell,  and 

How  to  Become  Acquainted  with  it. 
Telephone  Transmitter  Batteries. 
Lightning — Its  Action  upon  Telephone  Apparatus 

— How   to    Prevent  or  Reduce    Troubles   Aris- 
ing Therefrom. 
The  Telephone  Inspector. 
The  Telephone  Inspector — His  Daily  Work. 
The  Inspector  on  Detective  Duty. 
The  Daily  Routine  of  the  Telephone  Inspector. 
Individual  Calls  for  Telephone  Lines. 
Telephone  Wires  versus  Electric  Light  WTires. 
Electric  Bell  Construction,  Part  I. 
Electric  Bell  Construction,  Part  II. 
Housetop  Lines,   Pole  Lines  and  Aerial  Cables. 
Anticipations  of  Great  Discoveries  and  Inventions. 

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TABLES    OF 

EQUIVALENTS  OF  UNITS   OF 
MEASUREMENT. 

BY    CARL    HERING, 

Author  of  "  Principles  of  Dynamo  Electric  Machines,"  etc. 


Bound  in  Flexible  Covers.     Price,  50  Cents. 


Electrical  measures  being  based  upon  the  metric 
system,  these  tables  have  been  carefully  calculated 
to  express  the  various  values  met  with  in  electrical 
literature  in  their  English  equivalents. 

CHART  OF  WIRE  GAUGES. 

By  S.   S.   WHEELER, 

Electrical  Expert,  New  York  Board  of  Electrical  Control. 

Engraved  on  fine  plate  paper,  and  suitable  for  framing, 


Price,       -       -       $1.00. 


By  means  of  the  engraved  curves  on  this  chart  of 
the  various  wire  gauges  of  the  world,  the  size  of 
wire  corresponding  to  any  number,  or  the  equiva- 
lent number  of  another  gauge,  can  be  determined 
at  a  glance. 

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PROCEEDINGS 

OF    T1IK 

National  Conference  of  Electricians 

AT     PHILADELPHIA. 


Cloth.    800  Pages.    23  Illustrations.     Price,  75  Cents. 


The  conference  of  electricians  held  in  connection 
with  the  International  Electrical  Exhibition,  at 
Philadelphia,  in  1884,  was  a  notable  gathering, 
and  the  discussions  of  the  eminent  American  and 
English  electricians  who  were  present  on  that  im- 
portant occasion  will  always  have  an  authoritative 
value. 

Among  those  who  took  part  in  the  Conference 
and  whose  views  and  opinions  are  preserved  in  this 
volume  were  Sir  Wm.  Thomson  (now  Lord  Kel- 
vin), Prof.  Rowland,  Prof.  S.  P.  Thompson,  Elihu 
Thomson,  W.  H.  Preece,  Prof.  Forbes,  Pro'. 
Newcomb,  F.  J.  Sprague,  and  many  others  of 
eminence  in  the  scientific  and  practical  world. 

Mailed  prepaid  to  any  address  on  receipt  of  the  price 
by  the  Publishers, 

The  W.  J.  JOHNSTON  COMPANY,  Ltd., 

TIMES   BUILDING,   NEW   YORK, 


A  BOOK  FOR  THE  LIGHTER  MOMENTS. 


Lightning  Flashes     /. 

and 

.'.     .*.    Electric  Dashes. 

A  Volume  of  Choice  Telegraphic  and  Electrical 
Literature,  Humor,  Fun,  "Wit  and  Wisdom. 


Cloth.   Profusely  Illustrated.    160  Large,  Double  Column 
Paa;es.    Price,  $1.50. 


"Lightning  Flashes"  is  principally  made  up  of 
short,  bright,  crisp,  ably-written  stories  and 
sketches  from  the  pens  of  the  foremost  writers  in 
the  ranks  of  telegraphic  and  electrical  literature,  as 
well  as  of  several  writers  of  prominence  outside  of 
the  business.  Among  the  latter  are  included  Mr. 
Charles  Barnard  and  the  late  Benson  J.  Lossing, 
LL.D.  The  article  by  Dr.  Lossing,  on  Professor 
Morse,  is  a  valuable  contribution  to  the  history  of 
the  telegraph,  and  the  other  articles,  grave  and  gay 
in  turn,  in  some  cases  illustrated  by  the  authors, 
make  this  a  work  of  interest  to  the  general  reading 
public  as  well  as  to  electricians. 

Mailed  prepaid  to  any  address  on  receipt  of  the  price 
by  the  Publishers, 

The  W.  J.  JOHNSTON  COMPANY,  Ltd., 

TIMES  BUILDING,   NEW  YORK. 


:RIRST 


WIRED  LOVE: 

A  ROMANCE  OF  DOTS  AND  DASHES. 
By  ELLA  CHEEVER  THAYER. 

Fourth  Edition.     €loth.     »25«   Pages.     Price,  75  Cents. 


A  good  book  to  make  you  forget  business  and 
care,  and  leave  pleasant  memories  behind  it. — 
Chicago  Inter- Ocean. 

A  capital  love  story,  the  affection  having  its 
origin  in  telegraphic  communications  between 
two  operators  unknown  to  each  other,  fifty  miles 
or  so  apart. — Boston  Commonwealth* 

The  book  is  written  in  an  easy,    off-hand  style,   • 
pervaded   with   quiet  humor,    and   its  sentimental 
portions  contain  some  suggestions  of  wisdom  that 
are  expressed  with  great  force,  beauty  and  origi- 
nality.— Boston  Herald. 

The  love-making  which  goes  on  is  done  over 
telegraphic  wires,  and  there  is  plenty  of  humor 
and  a  dash  of  mystery  about  the  story  which  makes 
it  refreshing  reading.  The  heroine  is  a  telegraphic 
operator,  and  the  way  in  which  her  acquaintance 
over  the  wires  with  a  fellow-operator  ripens  into 
something  more  than  friendship  is  very  pleasantly 
told. — Boston  Journal. 

Mailed  prepaid  to  any  address  on  receipt  of  the  price 
by  the  Publishers, 

The  W.  J.  JOHNSTON  COMPANY,  Ltd., 

TIMES   BUILDING,   NEW  YORK. 


JOH  NSTO  N'S 

Electrical  and  Street  Railway 

DIRKC  TORY. 

CONTAINING    LISTS    OF 

CENTRAL   ELECTRIC  LIGHT  STATIONS, 
ISOLATED    PLANTS. 

ELECTRIC  MINING    PLANTS, 

STREET    RAILWAY  COMPANIES 
(Electric,  Horse,  and  Cable). 

WITH  DETAILED   INFORMATION  REGARDING  EACH. 
ALSO 

LISTS  OF  ELECTRICAL  AND  STREET  RAILWAY- 
MANUFACTURERS  AND  SUPPLY  DEALERS, 
ELECTRICIANS,  ETC. 


•  PUBLISHED     ANNUALLY.  H 


Substantially  bound  in  Cloth,          -          Price,  $5.00. 


The  great  facilities  possessed  by  THE  ELECTRICAL 
WORLD  for  obtaining  information  in  every  branch 
covered  by  the  Directory,  added  to  the  special 
facilities  of  the  Directory  department  itself,  guar- 
antee that  this  work  will  ALWAYS  be  the  MOST 
COMPLETE,  the  MOST  RELIABLE  and  the 
MOST  VALUABLE  of  any  work  of  the  kind 
EVER  ISSUED. 

Mailed  postpaid  to  any  address  on  receipt  of  the  price 
by  the  Publishers, 

The  W.  J.  JOHNSTON  COMPANY,  Ltd., 

TIMES   BUILDING,  NEW  YORK. 


The  Pioneer  Electrical  Journal  of  America. 


READ  WHEREVER   THE    ENGLISH    LANGUAGE 
IS    SPOKEN. 


The  Electrical  World 

IS    THE 

Largest,  Most  Handsomely  Illustrated,  and  Widest 

Circulated  Electrical  Journal 

in  the  World. 


It  should  be  read  not  only  by  every  ambitious 
electrician  anxious  to  rise  in  his  profession,  but 
by  every  intelligent  American. 

The  paper  is  ably  edited  and  noted  for  explain- 
ing electrical  principles  and  describing  new  inven- 
tions and  discoveries  in  simple  and  easy  language, 
devoid  of  technicalities.-  It  also  gives  promptly 
the  most  complete  news  from  all  parts  of  the  world, 
relating  to  the  different  applications  of  electricity. 


Subscription,  including  Postage  in  the  U.  S.,  Canada,  or 
Mexico,  $8.00  A  losir. 

May  be  ordered  of  any  Newsdealer  at  10  cents  a  week. 

'      (J* 

The  W.  J.  JOHNSTON  COMPANY,  Ltd., 

TIMES  BUILDING,   NEW  YORK. 


YA  0220 


YA  02201; 


THE  UNIVERSITY  OF  CALIFORNIA  LIBRj 


